An AdLib ISA card!
HardwareSpeak of the devil, Wikipedia has a photo of an AdLib sound card from 1990, in all its ISA glory!
Granted it was merely an interface and vessel for a general PC to use the Yamaha YM3812 sound chip, but for the time it must have been pretty exciting to hear that level of detail on a PC. Home computers like the Commodore 64 already had sophisticated MOS synthesiser chips since the early 1980s, but Big Blue made work machines!