No doubt you've seen the round of obits of producer Teo Macero (NY Times, LA Times, Pitchfork). Some might say Teo wouldn't be remembered as easily if not for his presence on Miles Davis's best-known albums, but many more would say that's a vast underestimation of his influence. His legacy is indeed closely linked to Miles's and we might not be as ready to give a producer the same credit and respect due to a musician, but (1) he actually was a musician himself, a saxophonist and composer, and (2) his storied contributions to Miles's finest works go above and beyond mere session supervision or artistic advisement. Miles's daring, prescient concepts are, of course, the main dish, but Teo's significant, pioneering producer-ly touches give them a more appealing presentation. Arguably, his razor-and-reel sound manipulation shouldn't be remembered as "the entire point of the exercise" as he believed (see the NYT article), but his legacy holds up all the same -– and to the benefit of the music, in my view, the issues surrounding Quiet Nights notwithstanding. And it's worth acknowledging his supervision of Mingus's fine Columbia work (notably Ah Um and Dynasty) and, of course, Brubeck's Time Out.
In any case, if Teo hadn't made his mark as a producer, his musical talents would have likely come to the fore all the same. His compositional and performance skills are well documented on record. Kyle Gann's blog, PostClassic, has a very cool mp3 of Macero performing an original quarter-tone piece. Darcy has some good links as usual, including a video interview of Macero and a personal anecdote. Also check out this WCPN interview with Bobby Jackson from June 2001 and a great Q&A with Perfect Sound Forever from September 1997. (Note Teo's response about "the purists.")