Massive, epic talent. Did everything by ear and instinct, never learned to read or write music. Incredible feel for timbre, melody, and structure.

The DX7 synth used to have a ridiculous "chuff chuff chuff DING!" comedy steam train preset. It sounded terrible and was utterly useless except as a 10 second novelty.

He used it in one of his soundtracks - and somehow made it perfectly musical in that setting.