Matt Yglesias and Ezra Klein have posts on the minutiae of the Obama and Clinton campaigns. While I sympathize with the former's sighing frustration with time wasted discussing this kind of thing, I would also argue that it is important. This kind of thing, as trivial (even nonsensical) as it seems tells us a lot about a candidate. Remember candidate Clinton blowing (OK, maybe that was poor word choice) his sax on one of the late-night shows? Remember "Don't Stop (Thinking About Tomorrow)", the 1992 campaign theme? Shoot, you can look up in a history book about the importance of Roosevelt's choice of "Happy Days Are Here Again" as a campaign song.
These things create a mood, tell us who these people are as people, and their personal styles. The difference between Celine Dion and Curtis Mayfield is huge, and speaks volumes about who Hillary Clinton is as opposed to Barack Obama (God knows, I'd vote for Mike Huckabee if he listened to "Superfly"). The fact is people make political decisions and choices based on all sorts of information, and sometimes trivial things like this tell us more than a person's preference in music (or in Sen. Clinton's case, non-music; please, Hillary, Celine Dion?). They tell us about risk-taking, about an openness to innovation and newness, about how they view their lives.
Right now, I've got Slayer playing on Pandora - and I think an outsider would consider that important. Taking in to account my self-professed Christianity, that I would sit and blast out my little 6 watt laptop speakers with some good old-fashioned death metal might cause some to pause. They might even want to know what else I find worth listening to, and how that works itself out in my life.
So, yeah, it's trivial. That doesn't mean it's unimportant. In fact, I would much rather have a President who dug Stevie Wonder (I would treasure a copy of any of my old Stevie Wonder LPs signed by both men) than one who listened to Adult Contemporary. The former knows music. The latter just likes background noise. One likes inspiration. The other likes to have something playing to keep the silence at bay.