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It was not until 1978 that the problem was resolved satisfactorily. The five-voice polyphonic
Prophet-5, released by American company Sequential Circuits, was the world’s first
synthesizer with a global storage facility. All settings for each of its five onboard
monophonic synthesizers were stored in memory slots—40 in the debut model. Moreover,
all five synthesizers shared a single user interface, which simplified matters considerably.
In spite of its initially steep price, this instrument proved extremely popular and
approximately 8,000 were built, up until 1985. In addition to its digitally implemented
polyphony and memory, the success of the Prophet-5 is attributable to the outstanding
quality of its analog sound generation system.
Digital Synthesizers
Even modern digital synthesizers featuring variable polyphony, memory, and completely
digital sound generation systems follow this semi-polyphonic approach. The number of
voices that these instruments are able to generate, however, is no longer dependent on
the number of built-in monophonic synthesizers. Rather, polyphony depends entirely on
the performance capability of the computers that power them.
The breathtaking developments in the digital world are best illustrated by the following
example. The first program that emulated sound generation entirely by means of a
computer was Music I, authored by the American programmer Max Mathew. Invented in
1957, it ran on a university mainframe, an exorbitantly expensive IBM 704. Unimpressively,
its sole claim to fame was that it could compute a triangle wave, although doing it in real
time was beyond its abilities.
This lack of capacity for real-time performance is the reason why early digital technology
was used solely for control (and storage) purposes in commercial synthesizers. Digital
control circuitry debuted in 1971 in the form of the digital sequencer found in the Synthi
100 modular synthesizer—in all other respects an analog synthesizer—from English
company EMS. Priced out of reach of all but the wealthiest musicians, the Synthi 100
sequencer featured a whopping total of 256 events.
Ever-increasing processor performance made it possible to integrate digital technology
into parts of the sound generation engine itself. The monophonic Harmonic Synthesizer,
manufactured by Rocky Mountain Instruments (RMI), was the first instrument to do so.
This synthesizer had two digital oscillators, combined with analog filters and amplifier
circuits.
The Synclavier, introduced in 1976 by New England Digital Corporation (NED), was the
first synthesizer with completely digital sound generation. Instruments like the Synclavier
were based on specialized processors, which had to be developed by the manufacturers
themselves. This development cost made the Synclavier an investment that few could
afford.
560 Appendix Synthesizer Basics