- Rockin’ Patent: US Patent No. 4,018,121
- Filed: 2 May 1975
- In the name of: (The Board of Trustees of) Leland Stanford Junior University
- Title: Method Of Synthesizing A Musical Sound
- What’s claimed: “A method of synthesizing a musical sound composed of a plurality of component frequencies and characterized by a time-varying amplitude envelope having a time-varying attack portion, a substantially steady-state portion and a time-varying decay portion, the steps comprising, generating a signal ωc to define a carrier frequency in the audio range, generating a signal ωm to define a modulation frequency in the audio range, generating a signal I(t) to define a time-varying modulation index, frequency modulating ωc with ωm to form a frequency modulated wave defined by e = Asin [ωc t + I(t) sin ωm t] where e defines the instantaneous amplitude of said wave, A defines the peak amplitude of said wave, and [ωc t + I(t) sin ωm t] defines the frequency spectrum of said wave wherein the frequency spectrum of said wave changes as a function of the modulation index I(t) to form a representation of said sound.”
- Why this patent rocks: This blog by -ajxs suggests that this patent appears to relate to the frequency modulation synthesis technology that forms the basis of the Yamaha DX7 synthesiser. For a detailed technical analysis of the technology and the engineering of the Yamaha DX7, see here.
If you’re a patent-savvy music tech business looking for patent help, get in touch with Russell IP here!
The information above is for general interest and information only and does not constitute legal advice.