The modern jazz small ensemble is built upon the rhythm section -- piano, bass, and drums.
The easiest parallel to programming is libraries, frameworks and patterns. These are the building blocks upon which we code. A well-designed library makes your work as a programmer easier and more enjoyable in the same way a solid, experienced rhythm section complements a soloist.
One important difference between programming and music is that in programming, correctness often supersedes aesthetics. It's not that aesthetics are unimportant, or that there can or should be no joy in programming -- but if your code doesn't work, it doesn't matter how much of a punk fringe rock star you consider yourself.
Color me (what, two nods to my pseudonym in two paragraphs?) uninspired. I doubt improv will pass my test suite. See Dabblers and Blowhards for a deeper debunking of similarly silly comparisons.