Frequency modulation allows the output of one oscillator to drive the frequency of another oscillator. It can generate very complex sounds from very simple waveforms and is the basis of the Yamaha DX range of synthisizers and OPL range of synthesizer chips (used in Adlib and most other soundcards)....
EML Synkey (advertisement)
A computer card-reader allows the musician to automatically position over twenty
sound-producing controls to create and recreate a voicing of the instrument. With the
card reader off, the instrument can be manually adjusted like a conventional
synthesizer. Another exclusive feature of the SynKey is a top-octave divider which
creates the sound effect of thirteen oscillators. The divider produces the basic root pitch
plus the next twelve higher semitones of that pitch in precisely spaced intervals.
The musician merely pushes the appropriate buttons to select the root pitch and any or
all of the semitones desired. The SynKey's 44-note keyboard also incorporates a
second touch feature. This lets the musician apply selective filter sweeps, vibrato or
third-of an-octave bend to individual notes simply by pressing harder on a key. Normal
pressure produces the note without modification.
Two models will be offered: the programmable model, and a standard model without
programming. The programmable SynKey will retail for $1995.00.