Yamaha · 1984 · 1980s–1990s · 8 voices
The YM2151 (OPM) was Yamaha's flagship 4-operator FM chip for arcade hardware through the mid-to-late 1980s, powering the sound hardware of Capcom, Konami, and SNK coin-ops and producing FM music of extraordinary sophistication.
The Yamaha YM2151, designated OPM (FM Operator Type-M), provided eight channels of 4-operator FM synthesis and was Yamaha's first FM chip designed with a dedicated LFO (low-frequency oscillator) for vibrato and tremolo effects at the hardware level. Its 8-channel output and fuller 4-operator architecture (compared to the 2-operator OPL family) gave arcade hardware composers a significantly richer timbral palette. The chip was central to the sound hardware of Capcom's CPS-0/early boards (Street Fighter, 1987), various Konami and SNK arcade PCBs, and Williams arcade hardware; it also appeared in the Sharp X68000 home computer as a flagship audio chip. The LFO capability in particular enabled the expressive pitch and amplitude modulation in brass, string, and electric piano patches that define the sound of late-1980s Japanese arcade music. Composers Manami Matsumae, Yoko Shimomura, and Tamayo Kawamoto all worked with YM2151-equipped hardware.