FM generates rich spectra with just two oscillator lookups, making it computationally viable for 1980s digital chips

Simple FM requires only two table lookups per sample: one for the modulator and one for the carrier. Despite this minimal computation, it generates spectrally rich, dynamic sounds controllable by a handful of parameters. This efficiency was the decisive commercial advantage in the early 1980s when chips were too slow for additive (N oscillators per partial) or analog-modeled subtractive synthesis in real time. The DX7 succeeded because FM gave a convincing range of timbres within the hardware constraints of the era.

Examples

Additive synthesis of a 32-partial sound requires 32 oscillators. FM achieves a comparable spectrum with 2 oscillators and 3 key parameters (fC, fM, I).

Assessment

Explain in two sentences why FM was commercially dominant over additive synthesis in the 1980s.