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Andrea Baroni

A BRIEF HISTORY OF SYNTHESIZERS

INDEX 1. In the beginning… a brief history of modern synths’ ancestors…………………………………………………………………………….3 2. Understanding synthesizers…………………………….……..………..........7 2.1 What is a Synthesizer?.........................................................................7 2.2 The characteristics of sound and its perception...…………………....…7 2.2.1 Pitch………………………………………………………….....8 2.2.2 Loudness………………………………………………………..8 2.2.3 Timbre…………………………………………………………..8 2.3 Different types of synthesis………………………………………………..9 2.3.1 Additive synthesis…………………………………….……......9 2.3.2 Subtractive synthesis……………………………………..……9 2.3.3 Frequency Modulation……………………………….……….10 2.3.4 Wavetable synthesis……………………………….……..….10 2.3.5 Linear arithmetic synthesis………………………….........….11 2.3.6 Physical modelling……………………………………....……11 2.3.7 Other types of synthesis…………………………………...…12

3. From first analog synths to modern software synths……..……........13 a. b. c. d. e.

First Experiments…………………………………………………………13 Moog and the first affordable analog synthesizers…………………...14 Microprocessor controlled and polyphonic analog synthesizers…….16 The digital revolution……………………………………………………..17 The virtual revolution……………………………………………………..20

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CHAPTER I In the beginning… a brief history of modern synths’ ancestors

The synthesis is a process through which, also artificially, you get compounds starting from simpler elements. If we consider tha matter carefully, the words we often use to describe the world all around us take much more information than we believe. In one of its meanings also just the word “synthetic” has today become a synonym of something produced artificially, that is by means of processes which copy the natural ones. Why then dwelling upon a word such as “synthesis”? What is the aim of this introduction in a subject about electronic music and modern musical instruments commonly known as synthesizers? Because, as it will later be dealt, before speaking about synthesizers it is necessary to understand what the basis of reproducing and syntesizing sounds is, and which processes make you replicate that peculiar acoustic sensation linked to some physical phenomena (the tweak of a string, the impact of two objects, the air getting through a tube). This topic has always been the cause of man’s curiosity and study since ancient times. Therefore it should not be singular to deal upon syntesizers starting from times when we could not even imagine the concept of elettricity. Great part of what was done since the beginning of the 20th century influenced the evolving course of modern keyboards, synths and generally speaking of electronic music.

Though electricity is the modern man’s child, mechanics is actually an ancient science, also automatism and reproduction of sounds and music by means of machines is a matter dating back to the ancient Greeks. The Greek engineer Ktesibios, who lived in the 3rd century B.C., in order to give an answer to the question “How can you play more than one instrument at a time?” designed the Hydraulos (see figure 1.1). It was a machine basically made up of a tube placed inside a tub filled with water by means of a pump. The pressure was set by the water weight, and a series of mechanical levers and devices would push the air through separate tubes, just in accord with the same concept which rules modern pipe organs. Organs can be actually considered as the 3

first rudimentary example of additive syntesizers, which as a matter of fact get their sound by making up a series of harmonics varying as time passes. All this to let a single person play insruments of harmonic complexity which was impossible to reach till then by means of the use of a single instrument. Let’s still remain in ancient Greece, the aeolic harp is conversely the first example of completely automated instrument. This instrument was made up of two bridges crossed through by strings. It was the wind itself which would generate music by passing through them. Figure 1.1 – the Hydraulos

After a fairly great temporal jump, we are in the 15th century when the hardy-gurdy, the ancestor of the grinder organ, was invented. This was at a certain extent the ancestral forerunner of something which can be defined as an instrument with a sequencer, that is a way of automatically reproducing a melody or a pattern of notes. If we temporarily diverge from musical instruments, we can take into consideration a device which had a huge impact on the modern age: in 1641 the adolescent Pascal invented the first adding machine, the Pascaline, which is to be considered as the forerunner of modern computers and therefore of modern digital synths. We arrive in the 18th century when esperiments on electricity get greater and greater interst and so do the machines which use it. The first real electrical instruments of history: the Denis d’or (the Gold Denis) and the Clavecin Electrique (electric harpsichord) by Jean-Baptiste de La borde date back to the mid of the century. In the latter, by using a small keybord, just like the one of the harpsichord, you could control a series of hammers which, being charged with static electricity, would ring small bells. Few years later the Panharminicom appears. This is a mechanical instrument provided with a keyboard which played automating flutes, clarinets, trumpets, violins, drums and other instruments. It was created by Johann Maelzel who even persuaded Beethoven to compose for his invention. Even though the Panharmonicon was a mechanical and not an electric instrument, the idea which forms the basis of this invention is the one which can be found inside modern sampling instruments. Going back to the first electrical instruments, the conception of the electromechanic piano is due to Hipps (whose first name is unknown). This instrument was essentially composed of a 4

keyboard which would activate some electrical magnets.These in their own right would activate some dynamos (small electrical current generators), the devices actually responsible for sound production. They were the same dynamos which, almost a century later, would be used in Cahill’s Teleharmonium. Elsha Gray, the inventor of the telephone (just like Bell, who first however got the patent) created the electroharmonic telegraph. Here, for the first time some oscillators appeared. As a matter of facts Gray discovered how to reproduce a self-vibrating circuit, substantially a frequency oscillator. This system, which originally was thought to transmit music through telephone wires, was adjusted by Gray to be used regardless of a telephone and by means of a speaker to output sounds. For the record, Alexander Bell himself released a similar instrument which he called electric harp. It was on the verge of the 19th century that music was first thought not only as a performance but as a replication of a previous performance as well. The phonograph, invented by Thomas Edison in 1877 is actually the first device which lets you record any kind of sound on a physical medium, in this instance a waxen cylinder which is written on by means of a diaphragm provided with a nail. These cylinders would not last for a long time, yet Edison had first thougth of this invention to be used in business and working field. The same idea would be afterwards refined with the use of several kinds of cylinders or records, which would become our modern record players, the most

Figure 1.2 – Edison’s Phonograph

widespread system of sound reproduction for a long. The Player Piano was based on the same reproduction conception. This was invented in the U.S. in the late 19th century and enabled you to record a performance on a paper roller which could be copied and distributed to those who had the same instrumemt. So they could reproduce an identical performance in a way very similar to what is done with modern MIDI files today.

In 1898 Thadeus Cahil won a patent named “Art of and Apparatus for Generating and Distributing Music Elettronically”. His idea was to create an electric device by means of which music could be played and diffused to offices, hotels and houses through telephone 5

wires. The telharmonium ,or dynamophone, came so to light, which, like the electromechanical piano, see above, would generate sound by means of dynamos. These produced alternate current and gave birth to a sinusoidal wave, in this instance the dynamo was called alternator. This was released by means of electrical magnets and very large tone wheels. This instrument is considered by many the first additive synthesis device.

We will close this brief look of the ancestors of modern synths with something which perhaps approaches them the most, the Singing Arc, that is the first fully electronic instrument ever made. This was conceived by William Duddel who, to produce it, started from the technology used in the carbon arc lamp, a precursor of the bulb lamp. The problem of this light emitting device was that it was also a source of a great deal of noise, from a low hum to an annoying high frequency whistle. Duddel, a physicist who had been requested to inquire into the origin of the noise these lamps produced, discovered that the more current you would apply to the lamp, the higher sound frequency you would get. To demonstrate that phenomenon he connected a keyboard to the lamp which was so called Singing Arc. During a convention of elecric engineers in London this keyboard was connected to every lamp in the building, and it was discovered that not only they played all together but all the lamps connected to the same electric circuit of other buildings played contemporarily as well. It was so found a way to transmit music at a distance. No further development would follow neither Duddel requested a patent for this device. He started to go round the country to show his Singing Arc which soon became a downright novelty.

And so we close this short historical journey through the evolution of mechanical and electrical instruments which more deeply influenced the development of modern synths and more generally speaking of every analogic and digital instrument applied to electronic music. Before resuming the journey starting from the 20th century, in the next chapter we will see the exact structure of a synth, and which algorithms and techniques are used in sound production.

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CHAPTER II Understanding Synthetizers

As I have already stated at the beginning of the first chapter, to understand the history and the evolution of this peculiar “family” of instruments is necessary to know what sound generation is based on and to become clearly aware of the techniques used and of the algorithms which have been chosen in every type of synth.

2.1 What is a Synthesizer? It may sounds reductive but a synthesizer can best be defined as a device that constructs a sound by uniquely determining the fundamental elements of pitch, timbre, and loudness, that are the main characteristics of sound, as we will discuss later on. There are many different types of this instrument, but it is important to state that it is not a product similar to a motorcar, where various modes all perform more or less the same function, and it is not a machine, but a tool to create music with.

2.2 The characteristics of sound and its perception As a physicist might say, a sound is the result of a stimulus, caused by moving objects, induced in the ear by the vibrations of air particles. If the way the source object moves consists specifically in a periodical oscillation around a central point, and if the solid body which is invested by continual changes of pressure is the tympanic membrane of the ear, this phenomenon is exactly perceived as a sound.

What basically characterises a sound from a strict physical point of view are frequency and amplitude. The former, which is measured in Hz (cycles per second) is bound to the vibration speed of the source object, the latter, which is measured in decibel, is bound to the width, or more properly to the energy of oscillation itself. It is now necessary to point out the link occurring between the sound as a physical phenomenon and the corresponding sound sensation. So, the features of pitch, bound to

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frequency, of loudness, bound to amplitude, and of timbre which indicates the colour, or the quality, of a sound will be now taken into consideration. 2.2.1 Pitch Pitch is the quality of a sound which makes some sounds seem “higher” or “lower” than others. Pitch is determined by the number of vibrations produced during a given period of time, corresponding to the frequency of the sound signal. An average person can hear a sound from about 20 Hz to about 20,000 Hz. Above and below this range there is ultrasound and infrasound , respectively. The upper frequency limit drops with age. 2.2.2 Loudness Loudness is the amount or level of sound, that corresponds to the amplitude of the sound wave. A change in loudness in music is called dynamics, and is often measured in decibels (dB). Sound pressure level (SPL) is a decibel scale which uses the threshold of hearing as zero reference point. While there is technically no upper limit to amplitude threshold of hearing, sounds begin to damage to ears at 85 dB and sounds above approximately 130 dB (called threshold of pain) cause pain. Also in this case the range depends on the individual involved and on the age. 2.2.3 Timbre In music, timbre is the quality of a musical note which allows you to distinguish between different sound sources producing sound at the same pitch and loudness. The vibration of sound waves is quite complex, most sounds vibrate at several frequencies simultaneously and the additional frequencies are called overtones or harmonics. The relative strength of these overtones helps determine a sound’s timbre. Though the tone colour of the phrase is often used as a synonym for timbre, colours of the optical spectrum are not generally explicitly associated with particular sounds, the sound of an instrument is most likely described with words like warm, harsh, dull, brilliant, pure or rich.

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2.3 Different types of synthesis As by means of analysis it is possibile to get the main parameters characterising the spectrum of a sound signal, similarly the aim of synthesis is to artificially produce a sound with some required timbre features by generating a variation of electrical voltage by means of either analogic or digital techniques. In the latest decades a series of synthesis techniques have been realised and formalised. They differ (one from another) for the peculiar mode of use and the multiplicity of timbre features which can be obtained. The synthesis techniques which will be examined are the most significant from a historical and practical point of view. It is however important to underline that some of these techniques are not exclusive, that is they can be combined to obtain new more interesting sounds, what today happens in the software and hardware of modern synthesizers. 2.3.1 Additive synthesis The sound is constructed from the ground up by mixing (summing) together one or more basic and simple waveforms (like sine waves) and their harmonics. In figure 2.x there’s an illustration that shows how two sine waves can be summed to form a more complex waveform. This method of synthesis is theoretically capable of reproducing any sound. This is true because every sound can be broken down into a collection of sine waves. However, you need to add an enormous amount of harmonics to create a complex sound. From a digital point of view an additive synthesis is the sum of the samples of every sine wave which are measured at instants determined by sampling frequency. One of the most interesting features of this kind of synthesis is the possibility to define the volumetric course, that is the envelope of every single component. This makes it possible to produce sounds with a dynamic spectrum. One of the drawbacks of this technique is the fact that is very expensive in terms of computing time, making it difficult to use for real time sound generation. 2.3.2 Subtractive synthesis This process takes a reverse approach to generating sound. It is based on the complete or partial subtraction of some frequency components of an initial sound. This sound is usually a waveform rich with harmonics (like a square wave or better a white noise generator), and the frequencies are taken away by applying some specific 9

devices, called filters. Figuratively speaking, this technique resembles the action of a sculptor who, starting from a formless piece of marble subtracts material to define the required shape. This method can be used to effectively recreate natural instrument sounds as well as textured surreal sounds. Obviously the filters are crucial, the better the filters and the wider the choice of available filters, the better the end result will be. 2.3.3 Frequency Modulation (FM) This synthesis technique, still today one of the most used, is founded on the noted model of frequency modulation, to a large degree widespread in broadcasting field and which was extended to sound synthesis by Chowning in 1972. The output of one oscillator (modulator) is used to modulate the frequency of another oscillator (carrier). These oscillators are called operators. While in broadcasting the frequency of the carrier is very high (it is measured in Mhz) if compared with the frequencies in the modulating signal (typically audio range), as regards sound synthesis the frequencies of the two signals are comprised of the same width range FM synthesizers usually have 4 or 6 operators. Algorithms are predetermined combinations of routings of modulator and carriers. The envelope of the carrier characterises the envelope of sound itself, while the envelope of the modulator characterises the evolution of spectrum content. For these reasons FM synthesis is a very advantageous technique, because it makes it possible to obtain complex signals starting from two oscillators only, even if all the liberty which is permitted in additive synthesis is not present here; this because the spectrum components are bound by specific relations. This computational efficiency is the reason for this invention and explains its great popularity in earlier synthesizers and sound cards. 2.3.4 Wavetable synthesis This form of synthesis incorporates the use of pre recorded digitized audio waveforms of real or syntheitic instruments. In this way, the digital audio segments are stored as a table of waveforms in memory and played back at different speeds to produce output of a different pitch for each musical 10

note. A common addition to wavetable syntesis is that each instrument waveform contains a loop region. This region starts after the attack segment of the digital audio and repeats while the instrument’s note is sustained. Then the release segment of digital audio finishes off the note. Using envelopes and modulators these waveforms can be processed and layered to form complex and interesting sounds. It is clear, for this type of synths, how the physical memory is crucial to house the waveforms, so only in recent times this technique has been massively used. 2.3.5 Linear arithmetic synthesis (LA) First introduced by Roland in 1987 (as we will discuss later in the next chapter), this type of synthesis is based on the discovery that much of the information used to identify and categorise a sound is contained in the first few hundreds milliseconds. So, it takes short attack sampled waveforms, digitalized with the PCM (Pulse Code Modulation) technique, and combines them with synthesized sounds that form the body and tail of the new sound (also known as Sample & Synthesis technique). By layering these and combining them with the synthesized portion of the sound you arrive at the new sound, that is also processed by filters, envelope generators, etc.. This is one of the most common forms of synthesis used in the 90s and even today. 2.3.6 Physical modelling (PM) The synthesis techniques which have been analysed till now are based on mathematical algorithms . In the case of the imitation of the sounds of traditional musical instruments, these techniques are applied to signal generation, leaving aside the physical mechanism they are produced with, and taking into consideration only the analysis and synthesis of certain temporal functions. One of the main problems bound to these techniques is the absence of a well defined correspondence between the change of a parameter and the sound produced, making it less predictable So, this technique is based on trying to simulate the physical properties of a real or fictitious musical instrument mathematically by defining exciters and resonators. Exciters are what trigger the physical model to start generating sound. Real examples include the hit of a drum, the stroke of a bow or pluck of a string. An input (such as a key press and the velocity of the press) is translated into the appropriate parameters for simulating physical properties of instrument’s input (such as blowing, or amount of 11

air). Resonators simulate the instruments response to the exciter which usually defines how the instrument’s physical elements vibrate. This type of sound generation can be extremely complex and requires heavy computation, so many currently available physical modelling synths use short-cuts or watered-down methods which enable them to respond in real-time. One curious fact is that the Nord Lead (a famous synths producer) currently uses PM synthesis to emulate an analogue syntesizer. 2.3.7 Other types of synthesis There are some other synthesis techniques which, to be brief, will not be analysed in detail. One of the most important to be mentioned is the Granular Synthesis, in which tiny events of sounds (grains or clouds) are manipulated to form new complex sounds. By using varying frequencies and amplitudes of the sonic components, and by processing varying sequences and durations of these grains, a new complex sound is formed. Another one is the Amplitude Modulation Synthesis (AM) which is performed by combining two signals together, similarly to FM synthesis, where the carrier is multiplied by an unipolar modulation signal, that determines the audio singal amplitude over time. The Ring Modulation Synthesis (RM ) is almost identical to AM syntesis with the exception that it a bipolar modulation signal. A bipolar singal is simply a signal that has positive and negative value, causing an interesting difference in the output signal when compared to AM synthesis. This type of modulation is used by vocoders which are often used to effect a human voice’s sound signal to create a robotic sounding variation.

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CHAPTER III From first analog synths to modern software instruments

As I have dealt with what was done at the beginning of the 20th century and the concepts lying in modern synthesizers and their sound generation, now I am going to speak about their origin and evolution, from the very first experiments till today.

3.1 First experiments The experiments on the sound generation and the ways it is reproduced, which has been dealt with in the first chapter, of course went on successfully. Then, lots of the synthesis algorithms described in the previous chapter were defined. The additive synthesis, already present in all kinds of organs (including the acoustic one), became very popular with the most synth-like of the organs, the Hammond, whose invention dates back to 1929. It would become a real legend, both for its unique sound and for the innovation it brought to modern music. The Hammond uses sine waves generated by revolving tone wheels (a relatively primitive apparatus for generating electronic musical notes), which induced a current in an electromagnetic pick-up. For every harmonic, there had to be a separate tonewheel. But we have to wait up to the middle of the century to see the first model of synthesizer similar to the ones we know today. In the 50’s would

RCA produce

experimental devices to synthesise

both voice

and music. One of the most important of this devices was created in 1955 by Harry Olson and Belar, both working for RCA. They invented Figure 3.1 – Olson and Belar with their Electronic Music Synthesizer

the Electronic Music 13

Synthesizer, also known as Olson-Belar Sound Synthesizer. This huge and unwieldy system (see figure 3.1) was controlled by a punched paper roll, similar to a player piano roll. A keyboard was used to punch the roll and each note had to be individually described by a number of parameters (frequency, volume, envelope, etc.). The output was fed to disk recording machines, which stored the results on lacquer-coated disks. Programming this machine must have been a laborious and time consuming process, but it caught the attention of electronic music pioneers such as Milton Babbit. The passage from organs to synths was however gradual and produced lots of very interesting hybrids. Though even nowadays organs and synths are classified as differentiated musical instruments, the sound generation occurring inside is based on common principles. In 1967, for example, Tsutomu Katoh, the founder of Keio (which subsequently would be called Korg), asked Fumio Mieda, an engineer who wanted to develop musical keyboards, to design and realise a keyboard to be built and sold. The Korg Organ was so born (see figure 3.2), which differently from other organs on the market could program voices. Figure 3.2 – the Korg Organ

3.2 Moog and the first affordable analog synthesizers The synthesizers made in this early time were however very expensive and also very hard to handle. By 1960, synthesizers could be played in real time but were confined to studios because of their sizes. Modularity was the usual design, with standalone signal sources and processors being connected with patch cords or by other means, and everything was controlled by a common controlling device. Donald Buchla, Hugh Le Caine, Raymond Scott and Paul Ketoff were among the first to build such instruments, in the late 1950s and early 1960s. Only Buchla later produced a commercial version. It was the year 1963 when Robert Moog, an engineer and a physicist of Dutch origins, founded the R. A. Moog Co. in Trumansburg near Ithaca, NY.

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Becoming one of the most legendary synthesizers producers, he created the first playable modern configurable music synth, and displayed it the Audio Engineering Society convention in 1964. So, starting at first as a curiosity it caused a real sensation by 1968. The Moog Modular synthesizers (see figure 3.3) became the first embodiment of the modern analogue synths. To get a sound you had to plug each module into another. You

couldn’t

memorize

sounds (you had to draw the connections on a sheet of paper) and the keyboards were monophonic (only one note at a time), but you could

create

an

infinite

number of sounds. Though Donald Buchla got started a few months

Figure 3.3 – Moog Modular model 3C

ahead of Moog, the first Buchla Box would appear later. They are very similar: both are modular and use voltage control for the oscillators and amplifiers, but the Buchla Box consciously avoids keyboard controllers. Other early commercial synthesizer manufacturers included ARP, by Alan Robert Pearlman, who also started with modular synthesizers before producing all-in-one instruments, and British firm Electronic Music Systems. One major innovation by Moog was in 1971, when they made a synthesizer with a built-in keyboard and without a modular design. The analog circuits were retained, but made

interconnectable

with

switches

in

a

simplified

arrangement

called

"normalization". Though this design was less flexible than modularity, it made the instrument more portable and its use much easier. This first prepatched synthesizer, the Minimoog (see figure 3.4), became very popular, with over 12,000 units sold. It also deeply influenced the design of nearly all subsequent synthesizers. Korg,

too,

created

a

similar

instrument in 1973, the Mini Korg, a

Figure 3.4 – the MiniMoog 15

very small monophonic instrument, whose success convinced the company to invest substantial resources to develop further synthesizers. So, by the beginnings of 1970s, even if the market demand for organs such as Balwin, Hammond and Lowrey was clearly higher, the one of synth keyboards was starting its small expansion thanks above all to miniaturized solid-state components that let synthesizers become self-contained and movable. They began to be used in live performances, becoming soon a standard part of the popular-music repertorire (Giorgio Moroder’s “Son of my father”, 1971, became the first #1 hit to feature a synthesizer).

3.3 Microprocessor controlled and polyphonic analog synthesizers Early analog synthesizers were always monophonic, producing only one tone at a time. A few, such as the Moog Sonic Six, ARP Odyssey and EML 101, were capable of producing two different pitches at a time when two keys were pressed. Polyphony, or the ability to play simultaneously multiple "voices", each having its own pitch (thus allowing the playing of chords), was only obtainable with electronic organ designs at first. Popular electronic keyboards combining organ circuits with synthesizer processing included the ARP Omni and Moog's Polymoog. Around the middle 70s the first polyphonic synths started to be produced. For example the Oberheim SEM, with which you could play 2, 4, 6 or 8 notes at the same time, depending on the models, and provided with 16 memory slots, a kind of experimental memory which could memorise, for each module, a couple of parameters. A classic huge (it weighs over 200 lbs) polyphonic synthesizer is the Yamaha CS80 (see figure 3.5), to be considered as the first Japan’s great synthesizer. Born in 1976 as a development of the GX1 model at an affordable price range was a complex polyphonic synth, with some amazing features for its time, like 16 oscillators, 32 filters,

Figure 3.5 – the Yamaha CS-80

32 envelopes allowing voices to be split and layered, and stored in a six part memory allocation. The keyboard was velocity sensitive with poly-aftertouch sensivity, that

16

means that it used a sensor for each key. It supported also a primitive sound settings memory based on a bank of micropotentiometers. When microprocessors first appeared on the scene in the early 1970s, they were costly and difficult to apply. The first practical polyphonic synth, which was also the first to fully apply a microprocessor as a controller, was the Sequential Circuits Prophet-5 (see figure 3.6) in 1977.

For

musicians

the had

first a

time,

practical

programmable polyphonic (5 notes) synthesizer that allowed all knob settings to be saved in computer memory (32 digital memory slots to record all the synth’s parameters). The Prophet-5 was also physically Figure 3.6 – Sequential Circuits Prophet-5

compact

and

unlike

its

lightweight,

predecessors. This basic design paradigm became a standard among synthesizer manufacturers, slowly pushing out the more complex (and more difficult to use) modular design.

3.4 The digital revolution The so called digital revolution transformed technology that previously was analog into a binary representation of ones and zeros. By doing this, it became possible to make multiple generation copies that were as faithful as the original. In digital communications, for example, repeating hardware was able to amplify the digital signal and pass it on with no loss of information in the signal. We have at last arrived in the early 80s and this rank revolution seems to fully invest the market of electronic musical instruments as well. The new digital synthesizers use digital signal processing (DSP) techniques to create musical sounds, which actually bases on the discrete representation of a continuous analogue signal. One of these techniques is the Pulse Code Modulation, where the magnitudo of the signal is sampled regularly at uniform intervals, and where every sample is quantized to a series of symbols in a digital binary code. 17

So, generating a digital sample corresponds to a sound pressure at a given sampling frequency (typically 44100 samples per second). In the most basic case, each digital oscillator is modelled by a counter. For each sample the counter is advanced by an amount that varies depending on the frequency of the oscillator (see Par. 2.3, Different types of synthesis, for further details). The world of synthesizers became dominated by the FM synthesis model, which uses sine-wave oscillators, which to be sufficiently stable needs to be generated digitally. The first patent covering FM sound synthesis was licensed in 1980 to Japanese manufacturer Yamaha, that produced in 1983 the first FM digital keyboard, the DX-7 (see figure 3.7). It was about the same size and weight as the Prophet-5 and was reasonably priced. No more front buttons but a set of countless preset banks

(sound-programmed

in

factory). The quality and precision of the sounds were increased, and so was the sound tuning, compared to the previous synthesizer generation. The

Figure 3.7 – Yamaha DX-7 digital synth

DX-7 was a smash hit and may be heard on thousands of pop recordings since 1980s. When Yamaha later licensed its FM technology to other manufacturers almost every personal computer in the world contained an audio input-output system with a built-in 4 oscillators FM digital synthesizer. Another very important invention date back to 1983, the MIDI, a digital control interface, making synthesizers more usable and versatile. The so-called General MIDI (GM) standard was devised in the late 1980s to serve as a consistent way of describing the set of synthesized tonalities available to a electronic digital instrument (or also a Personal Computer) for playback of a musical score. This kind of interface and protocol of communication (together with the file format .mid) are important standards in use even today. Roland, another great Japanese electronic instruments manufacturer, entered its gold era truly with the advent of the digital synthesis. It was 1987 when Roland released the D50 (see figure 3.8), a synth that had to become Roland’s standard keyboard: great velocity and aftertouch sensivity, with splits and layers. It was also 18

expandable,

with

options for ROM and RAM cards, a good MIDI implementation, a

programmer,

and

eventually third party Figure 3.8 – Roland D50

expansion boards. But

the most important reason for its success, being able to topple the DX-7 from the throne it had occupied for four years, was the fact it sounded amazingly, thanks to the new LA synthesis, developed by Roland itself in those years. The enormous popularity of the D50 caused a whole support industry to spring up. For many users it was unnecessary to learn how to program the instrument, they simply plugged in their favourite sounds and played. The possibility to digitalize a sound source created a new brand of electronic instruments: the samplers. A sampler is a device that can record and store audio signal samples, generally recordings of existing sounds, and play them back at a range of pitches. An early form of sampler was the Mellotron, which used individual prerecorded tape loops, one under each key on the keyboard. Sampling can also be used in combination with other synthesizer effects, processing it with filters, reverbs, ring modulators and the like. By the end of 1985 sampling had been around for six years. The affordable end of the market was dominated by the Ensoniq Mirage, while Kurzweil end Emu dominated the high end. Roland tried to fill the gap between them with the S50 sampler, a very good and innovative instrument, with 16-voice polyphonic, multitimbral, velocity and pressure sensitive, and offered splits, layers, and velocity crossfading. The S-50 could have been a winner, but Roland had come to the market a bit too late. Akai launched their S900 the same year (1986) and estabilished itself as the de facto standard (see figure 3.9).

Figure 3.9 – Akai S900 sampler

19

So, history of synthesizers continues in the latest years, with old and new leading manufacturer names such as Yamaha, Roland, Korg, Kurzweil and Alesis. Most modern synthesizers are now completely digital, including those which model analogue synthesis using digital techniques. These keyboards are now, in many cases, real workstations, integrating wider and wider sound banks, advanced sequencing functions, midi recording, sampling and even mastering and video signal transmitting capabilities. Figure 3.11 – Korg Triton Studio

3.5 The virtual revolution With the increase of computing power of modern CPUs and thanks to the diffusion of professional audio boards at affordable prices, personal computers have lately performed their rising in the world of recording and sound reproduction, in a particular field and system known as home recording. This let people achieve results which only advanced recording studios could afford to only few years ago. If this revolution has at first involved audio recording programmes (midi and audio sequencer, audio editor and complete systems of hard disk recording), in these days, even synths are experiencing an interesting period of computerisation. What was once computed by dedicated hardware (the one actually inside a synth), today can be entirely (or almost) operated by a single PC processor. A variety of software is available to run on modern high-speed personal computers and DSP algorithms are commonplace, permitting the creation of fairly accurate simulations of physical acoustic sources or electronic sound generators (oscillators, filters, VCAs, etc). Thanks to this new generation of so called “soft-synths” lots among the old synthesizers are experiencing a kind of second youth. Renowned models such as Moog Modular, Arp 2600, Yamaha CS-80, Prophet 5 have returned to the front of the stage. They are back not only as digital devices, where the sound is recreated by means of algorithms of simulation, but even as software, that is in the form of stand-alone programmes or even plug-in which can be run from modern sequencer like Cubase SX, Pro Tools, Sonar and Logic. Figure 3.11 shows the new “reincarnation” of Moog Modular by Arturia software house . It may be of a certain interest to notice that, in 20

spite of the modern plug-in approach, they try to retain the look and feeling of the old analogue hardware model, with for example the use of the old jack link cables (yes, even this stuff has been emulated!). These features do not bewilder musicians familiar with particular procedures and let them continue working using the more

versatile

and

comfortable

virtual release of their favourite synthesizers. But soft-synths are not only an emulation of old analogue synths. In actual fact, today you can have at Figure 3.11 – Arturia Moog Modular V soft-synth

your disposal impressive banks of every kind of sounds which software

samplers as renowned Native Instrument Kontakt and Steninber Halion are capable to manage in real time so easily and efficiently as it was not even possible with hardware samplers. The virtual revolution has got some synths which made the history of music not only to be recreated and improved, but they have been made affordable to a higher and higher deal of musicians, as they quote sensible lower prices and, thanks to their noticeable easiness, require a more casual use. Besides, with a further increase of computing power, a lot of synthesis algorithms may be later on improved; which will get sound generation more and more powerful and versatile.

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