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Old 11-18-2013, 06:49 PM   #1 (permalink)
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Default A Concise History of Synthesation

A tone has three main components that define it: 1. Pitch, 2. Volume, and 3. Timbre. What is timbre? Every tone has a sine wave and an overtone series. This series consists of natural harmonics that accompany the fundamental sine wave. A guitar sounds the way it does due to the accents in its harmonic series. Certain harmonics are accented while others are not. We call this characteristic of sound timbre (pronounced “TAM-ber”). If we pluck the A-string open, the guitar’s timbre is different than a piano A-key in the same octave because the piano’s harmonic series is accented differently. If we take a piano’s overtone series and “freeze” it on a computer screen and then use software to change its overtone accents to be identical to that of a guitar, the note is now indistinguishable from a guitar because it has been altered to mimic a guitar’s timbre. Likewise a guitar’s timbre can be altered to sound identical to a piano’s timbre. And, yes, such software does exist and is, in fact, very common. But before computers, analog synthesizers were doing this electronically.

In analog synthesation, there are seven essential components a synthesizer must have to be worthy of the name:
1. A VCA or voltage-controlled amplifier
2. A VCO or voltage-controlled oscillator (usually two)
3. A filter
4. A volume envelope generator
5. A filter envelope generator
6. A pitch envelope generator
7. An LFO or low frequency oscillator

Most synths have more than these but these seven are fundamental to any synth. A VCA is an amplifier whose gain is controlled by a small applied voltage called a control-voltage. On a digital synth, the amplifier is often DCA or digitally controlled where the amplifier is controlled by a set of binary numbers. In either case, the amplifier determines amplitude.

The VCO is an oscillator controlled by a small applied voltage. It is responsible for pitch. On a digital synth, there is instead a DCO, an oscillator controlled by a set of binary numbers.

The filter controls brightness by slightly varying the timbre. The filter will have an adjustable cut-off point and a resonance adjustment. Resonance accents various frequencies around the cut-off point resulting in unusual effects.

The volume envelope generator generates a set of instructions that it gives to the amplifier to carry out. These instructions appear in the form of a graph depicting the ADSR envelope. ADSR stands for attack, decay, sustain and release. Attack describes how a sound starts off, decay describes how the attack fades, sustain describes how long the sound holds after the decay. Sustain can last as long as the key is held down or can fade arbitrarily or can simply cut off. Release describes how the sound fades away after the sustain period ends. An ADSR envelope graph:


ADSR envelope. The graph is amplitude vs. time. In this graph, the attack rises quickly to a maximum amplitude, decays quickly (albeit somewhat slower than the attack) and then goes into the release which subsides slowly in both amplitude and time. No sustain is shown here but would simply be a horizontal line between the decay and release stages showing how long the signal remained at a steady amplitude before being released.

The filter envelope generator likewise gives instructions to the filter which can be represented with an ADSR graph.

The pitch envelope generator gives instructions to the oscillator. Once again, this can be expressed as an ADSR graph.

The low frequency oscillator came in the 60s when modular synths were introduced and the effect was accidental but was found to be very useful. Today, they are built into synths. The LFO is a secondary oscillator that does not produce a pitch like the VCO. It is much too low to be heard—below the 20 Hz range. Its purpose is to modify the audible sounds in various ways without introducing any sound of its own and hence it is below the threshold of hearing. The LFO is patched to modulate parameters as amplitude (creating tremolo), pitch (creating vibrato), phasing, stereo panning, filter frequency, etc. The LFO is also adjustable to control the amount of modulation. Often, the LFO is not called out on the synth. Instead there will be a tremolo button, for example, that internally patches the LFO to the VCA or DCA when it is engaged.
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Old 11-18-2013, 06:53 PM   #2 (permalink)
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Elisha Gray was an electronics genius from a proper Quaker home in Pennsylvania. He became obsessed with the idea of transmitting electrical signals through wire and did much to improve the telegraph for which he was granted patents. For example, he patented a self-adjusting telegraph in the 1860s that automatically adapted to changing insulation conditions in the telegraph lines which cut down significantly on the amount of grounded lines that had to be rooted out and repaired since a line with a ground was useless but could take weeks to trace and fix which was unacceptable for an increasingly necessary technology of American life.



Elisha Gray (1835-1901). His business, Gray & Barton Co. out of Cleveland, was bought up in 1872 by Western Union and renamed Western Electric Mfg. Co. of Chicago which was later shortened to Western Electric. He retired from the company in 1874 to work on his own pet projects.

While tinkering with sound transmission in 1874, Gray built a self-vibrating electromagnetic circuit and found that he could control sound with it. By self-vibrating, we mean that the circuit generated a fluctuating field (i.e. the field was continuously expanding and collapsing a.k.a. cycling) at a certain frequency (i.e. a certain number of cycles per second a.k.a hertz). When anything vibrates fast enough, it produces a tone. In this case, the vibrating field caused the circuit to vibrate and produce a tone. The tone was too soft to be heard unless one stood very close to it in a quiet setting but the vibration could be transmitted over phone lines and be heard in the receiver. Basically, Gray had just invented the single note oscillator, the very principle of synthesation.

That same year, Gray patented a harmonic telegraph where these single note oscillators were grouped together, each having a different frequency and operated by its own telegraph key. Simple tunes could be played at one location and heard miles away at a telegraph station. He gave demonstrations of his device in Washington D.C. and New York. This harmonic telegraph could be properly called the first true synthesizer. Its use of telegraph lines to broadcast live music was the first example of “streaming.”

This gave Gray the idea of using steel reeds to transmit sound over the telegraph lines that could be activated by piano-type keys instead of telegraph keys. Each key activated its oscillator which would cause its reed to oscillate sympathetically. The two-octave keyboard permitted “familiar melodies” to be transmitted “through telegraph wire.” This was a great improvement on the harmonic telegraph and so Gray patented his new invention in 1875 as “the Musical Telegraph.” He built several models, one of which was hooked to a simple “loudspeaker” of his own design so it could be heard naturally (there was no electrical amplification yet). Gray’s invention gave him the idea of transmitting the voice over telegraph lines and so he did the original work on the invention of the telephone but lost out on his bid to be known as its inventor because Alexander Graham Bell (who many say stole Gray’s idea) beat him to the patent office by a couple of hours in March of 1876.


Elisha Gray’s Musical Telegraph.
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Old 11-18-2013, 07:02 PM   #3 (permalink)
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Thaddeus Cahill (1867-1934) was a lawyer and inventor who believed that Gray’s Musical Telegraph had far more potential and began to experiment with electronic keyboards on a grand scale.

The simple oscillators invented by Gray were too primitive for Cahill’s vision—they had insufficient power. He replaced them with tone wheels. Cahill’s tone wheels consisted of an AC synchronous motor that drove a gearbox that, in turn, drove a series of rotating discs. Each disc had a set of “bumps” on it and the number of bumps and the speed of the disc’s rotation determined its frequency and therefore its musical note. The note was picked up by a magnet wrapped in a copper coil (appropriately known as a “pickup” and the same as today’s pickups). Cahill not only had tone wheels for the principle notes, he added more to play harmonics. The tone wheels generated simple sine waves which sound rather flat. By adding harmonics to a sine wave, we can create any sound in existence.

So Cahill’s harmonic tone wheels enabled different harmonics to be activated which altered the timbre of the instrument and enabled it to mimic such instruments as flute, cello, trumpet, bassoon and so on. Cahill patented a keyboard that ran on this principle in 1896 and called it the Teleharmonium (a.k.a. a Dynamophone). Like Gray’s Musical Telegraph, the Teleharmonium’s sounds were made to be broadcast over the phone lines. The phone speakers were attached to large paper cones that enabled everyone in the room to hear the music—another primitive loudspeaker as electronic amplification was not yet known. The Teleharmonium had stops like a pipe organ that enabled instantaneous timbre modulation and there were several keyboard consoles to enable polyphony and foot pedals that added startling effects according to those who have heard the instrument.


Edwin Hall Pierce playing the Mark II Teleharmonium.

The problem with the Teleharmonium, as versatile and unusual as it was, was the sheer size and weight of it. Cahill’s first model, the Mark I, weighed seven tons. And if that sounds like a lot, the Mark II, weighed 200 tons! The Mark III also weighed about 200 tons. The Mark II cost an incredible $200,000 to build! Obviously, not many Teleharmoniums could be built at that price.

In fact, only one of each model was built. The instrument had its own hall in New York, Teleharmonic Hall, where the entire basement was filled with the electronics that were required (this was before vacuum tubes). Its power consumption was enormous. But Cahill and his backers were hoping to transmit live music to 10,000 or more remote locations via telephone lines. But there was also a problem with cross-talk when broadcasting music over phone lines. People found their conversations suddenly cut off by strange electrical music and people listening to the Teleharmonium transmitting to them from 30 or more miles away would hear snatches of phone conversation cutting in on their musical enjoyment. The Teleharmonium was more advanced than the medium chosen to broadcast it. The cart was hitched before the horse.


The Teleharmonium was like an iceberg—the visible part of it big enough and yet most of it was hidden below, mind-boggling in its enormity.


Thaddeus Cahill


Holes were cut in the floor to accommodate the huge number of wires and cables passing from the consoles to the electronics housed in the basement. There are no recordings of the Teleharmonium and none of the three models built have survived the ravages of time. Cahill’s company went belly up in 1912 when problems with phone line transmission proved insurmountable. Cahill’s brother owned the Mark I after Cahill’s death in 1934, the last surviving Teleharmonium, but it was destroyed in 1962.

Cahill’s indelible contribution to musical synthesis was the tone wheel, which was then used by the Hammond company for their electric organs and is responsible for their trademark sound. By adding extra tone wheels to modify timbre, Cahill also came up with the process of additive synthesis (which we will explain later), also picked up by Hammond. An unexpected side effect resulted when Hammond’s tone wheels were so tightly packed that they sometimes picked up frequencies from adjacent tone wheels, a bleed-through resulting in a harsh, overdriven sound. Initially viewed as an undesirable characteristic, rock and blues keyboardists loved the effect and used it quite often making it rather famous. Today, many electronic organs and digital synths actually have presets for this effect.

Cahill’s invention was doomed no matter what. Once electrical amplification came about in the 1920s, courtesy of Western Electric, the Teleharmonium was truly obsolete. The huge generators and switchboards produced sometimes as much as 14,000 watts of power simply because there was no electrical amplification. Pushing that wattage through phone lines and a small telephone speaker and concentrated with a horn or cone was enough to fill a room with sound but the power usage was untenable. With electrical amplification, 100 watts fills a room easily. With loud concerts in an auditorium, 200 watts generally does the trick. At a large stadium, 500 watts is enough although some bands push it up to 1000 but this generally causes ringing ears in the morning. But 14,000 watts would blow out eardrums and drive sound waves through bodies so hard it would cause internal damage.

Cahill’s backer, Oscar T. Crosby, had hoped that the Teleharmonium could be used to replace the expensive orchestras that played at all the ritziest restaurants and hotels in New York. He could simply hire two musicians to broadcast live electrical music into the dining rooms and dancehalls throughout the city. Certainly an endeavor worthy of funding and experimentation, ahead of its time but that was the problem—the times weren’t ready yet and so the Teleharmonium fell by the wayside.


Interesting photo of a Teleharmonium demonstration. Note the huge horn speaker fed from a telephone receiver. Tremendous power was being generated but with no electrical amplification, the output was merely adequate. Although it looks easy to play here like any other organ, the Teleharmonium usually required two skilled musicians playing on a stack of keyboard consoles and modifying the parameters at the same time. The Teleharmonium was, in fact, a very awkward instrument to play and, in spite of its power, didn’t handle loud music well at all. People thought it too harsh. It turned into a glorified church organ—hardly suitable for dancehalls or ballrooms. Society orchestras were still safe from the unemployment line—for now.

A Teleharmonium documentary:

Magic Music From The Telharmonium Documentary - YouTube
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Old 11-18-2013, 09:06 PM   #4 (permalink)
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$200K for a glorified church organ? Nuts. That's gotta be over a mil in today's money?

Great thread too. As always.
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Old 11-19-2013, 04:33 AM   #5 (permalink)
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I completely love your threads. Keep them going
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Old 11-19-2013, 08:30 PM   #6 (permalink)
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In 1920, a Russian physicist named Leon Theremin came to the West at the behest of Lenin. Russia was largely seen by the West as culturally and technologically backward and Lenin wanted to change that perception. Theremin was also an inventor and had developed an electronic instrument quite unlike any before or since. Perhaps the only instrument that does not require the player to touch it in any fashion. The player instead moves his or her body in the space surrounding the instrument to alter its pitch and amplitude. Any movement of the body will register as a sound and so the instrument is difficult to play but, because the player is entirely freed from contact with the instrument, is extremely expressive. The sound is human-like, flute-like, violin-like and yet like none of these. Unmistakably electronic. The instrument is called, appropriately, the theremin.


Leon Theremin playing the theremin. The two perpendicular antennas pick up the movements of the player’s body—hands and arms in particular. The vertical antenna controls pitch and the horizontal one controls volume. The antennas control these parameters by means of oscillators. The closer to the antennas one places ones hands increases the volume or pitch frequency proportionally but completely independently of one another. The odd whistling tone has been used in many early sci-fi movies and also the theme song of My Favorite Martian as well as on the Beach Boys’ Good Vibrations.


Theremins are still very popular and this one is built from a kit. Thanks to technological advances, theremins are far more compact today.

Clara Rockmore plays “The Swan” by Saint-Saëns on the theremin:

Theremin - Clara Rockmore play "The Swan" (Saint-Saëns) - YouTube

Theremin came to the United States and patented his instrument in 1928 to RCA.
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Old 11-19-2013, 08:37 PM   #7 (permalink)
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That same year a new electronic keyboard was developed by a French cellist named Maurice Martenot. It was based on the same principles as the theremin. Called the Ondes Martenot (“Martenot Waves”), this was quite a revolutionary keyboard. The principle at work in the Ondes Martenot was the varying of frequency in vacuum tubes.


The Ondes Martenot. The console is played through a variety of speakers or diffuseurs. The bevel-top speaker contains a gong, the lyre-like speaker contains sympathetic strings and the rectangular speaker is ordinary. The speakers introduce further rather beautiful effects to the already cool sounds. The operator can turn any of the speakers on or off at will in any combination.


The Ondes keyboard is played with one hand since it is monophonic (only one key plays at a time). The left hand operates a control panel that fits in a little drawer. This panel controls various parameters as timbre, vibrato, etc. The large, white, rectangular button on the right is actually a kind of finger pedal. Left untouched, the keyboard is silent. As the button is depressed, the volume goes up. Pressing the button quickly causes a faster attack. The player continually works the button with the left hand while the right hand plays.


The player can also wear a special metal ring which he runs along a metallic ribbon installed in front of the keyboard. There is a metal marker plate under the ribbon marking off notes. The ribbon is a resistor wire. If the player slides his finger along the ribbon and touches the wear plate, the designated note will play because the metal-on-metal contact between resistor wire and ring forms a circuit which determines the amount of resistance in the circuit. He can jiggle his finger on the ribbon and get a vibrato effect. The point of using the ribbon and ring is that one note glides to another enabling microtonal instruments as cellos and violins to be mimicked. Of course, one can get the spacey theremin effects as well. The Ondes is like a contact theremin with the keyboard and ribbon controlling pitch with one hand and the amplitude button controlling volume with the other. The keys are also touch sensitive like modern synths. In fact, the Ondes is still being made in France where they still teach classes on its use. Trent Reznor of Nine Inch Nails also uses one.

An extremely cool demonstration of the Ondes Martenot:


Jean Laurendeau and the Ondes Martenot - YouTube
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Old 11-19-2013, 08:43 PM   #8 (permalink)
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A year after the Ondes Martenot was released, the Trautonium was released in Germany. This monophonic electronic device was invented by Friedrich Trautwein at the Rundfunkversuchstelle radio and music lab in Berlin.


Oskar Sala’s Mixtur-Trautonium.

Telefunken marketed the first Trautoniums in 1932 and produced 100 of them by 1935. The Trautonium had no keyboard but a resistor wire strung over a metal plate something like the Ondes Martenot and it ran on the same principle. Relaxation oscillators triggered first by neon tubes and then by thyratrons produced the raw sound in the form of sawtooth waves but later used transistors or UJT’s. The output of the oscillators was fed by parallel resonant filter circuits and the volume level of the two filters were controlled by footpedals. But this was not a poor man’s Ondes by any means; the Trautonium had a wider range of sounds.

Trautwein was joined by Oskar Sala. Sala added a switch for modifying the static tuning, then he added a noise generator and an envelope generator, then several band-pass filters and then subharmonic oscillators. Sala also added another manual. The oscillators did not play overtones but fractions of the overtones of the fundamental tone. Four waves could be produced and mixed for each of the two manuals and run through various presets. This device was called the Mixtur-Trautonium. Sala used this device to make the eerie bird noises in Hitchcock’s The Birds.

Unfortunately, there are no virtuoso Trautonium performances currently on Youtube. Here’s a guy goofing off with one but at least you can hear what it’s capable of:

Old Trautonium I Sold A While Back - YouTube
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Old 11-19-2013, 08:49 PM   #9 (permalink)
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In 1937, a Russian optical engineer named Evgeny Murzin developed a bizarrely different synthesizer that was photoelectrically operated. He named it after composer, Alexander Nikolayevich Scriabin, or ANS. The ANS synth interface is a glass plate covered with black mastic. This mastic is scraped off in the shape of a wave, any kind of wave. Photo cells then shine through the scraped area onto a bank of independently adjustable band-pass amplifiers which turn the light into pitches. Basically, it plays what is drawn. It has 720 available pitches and can play all of them simultaneously.


ANS synthesizer.


The Novachord was put out by Hammond starting in 1939 was pioneering being the first polyphonic synthesizer using subtractive synthesis. It contained over 160 vacuum tubes and 1000 capacitors. It weighed about 500 lbs and was as large as two upright pianos. It could play 72 notes, all of them at once if need be. ADSR envelopes were generated with switches and released with a pedal. It had very good timbre modulation. But the Novachord was beset with problems due to strict tolerances for its hundreds of components which made maintaining it difficult. Consequently, the Novachord never became a smashing commercial success and with the onslaught of the war it was soon forgotten. Hammond terminated production in 1942 after making 1069 of them. The Novachord can be heard in the movie Gone with the Wind and was heard in movie scores into the 60s. Only a few are still in service.


A look in the back of the Novachord at a few of its many vacuum tubes.
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Old 11-19-2013, 08:58 PM   #10 (permalink)
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After WWII, recording tape was introduced to the world. It had been invented by I.G. Farben, Nazi Germany’s answer to Dow Chemical, and it took the world by storm. At this time, Pierre Schaeffer had developed the concept of musique concrète which was music made from sources of sound whose origin is unseen. Tape furthered the vocabulary of musique concrète because of its malleable nature. A premier piece of musique concrète is John Cage’s 1952 tape collage, Williams Mix. Musique concrète was a virtual reversal of synthesation. Synths sought to construct the sound of ordinary instruments from purely electronic sources whereas musique concrète often mutated ordinary sounds acutely in order to disguise the source. In both cases, though, the source was hidden except in one case the source was electronic masquerading as natural and in the other the source was natural masquerading as electronic. The exception was when synths were used to generate purely electronic sounds that could not be produced any other way. In Williams Mix, Cage spliced the sources to very short durations and then had them all play very quickly in succession. The source was still instantly identifiable in some cases but not in others. Schaeffer’s 1948 piece, Etude aux Chemins de Fer, was composed of the various sounds made by trains and whistles recorded on discs but the sound of the phonograph stylus riding in the record groove becomes an integral part of the sound. Physicist/composer Hugh Le Caine’s 1955 tape piece, Dripsody, is composed entirely of a single recorded drop of water sped up, slowed down, and spliced in rapid succession until it sounds like an electronic keyboard playing up and down the scales. This could be done in a matter of minutes with a modern sampler but took Le Caine months of endless splicing to achieve.


John Cage - Williams Mix - YouTube


Hugh Le Caine: Dripsody (1955) - YouTube
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