Wikipedia citation: King's Quest IV was the first commercially released game for PC compatibles to support sound cards instead of only the standard built-in speaker.
Sierra took it seriously and hired professional musicians to kick off their effort.
Hollywood composer William Goldstein (Fame) was hired to compose King's Quest IV. https://www.youtube.com/watch?v=19r6RnReAf4
Supertramp drummer, Bob Siebenberg, composed the Space Quest III soundtrack. https://www.youtube.com/watch?v=dxEP05TtOfE