(or, the music you choose to listen to, to some extent).
A lot of Tories I know on Facebook seem to really dig classical music (which irks me, not that there's anything wrong with liking that kind of music, but when Tories (especially young Tories) do it, it just comes across as status-seeking). Most indie fans I've met seem to be very left-leaning, whereas the apathetic conservatives I know seem to exclusively like really middle-of-the-road, chart-topping stuff that everyone here hates.
I think it also depends on how clear an artist is in their agenda when producing music, in which case it can be liked by anyone who actually appreciates music (in the same way they appreciate art) and is willing to spend some time with it (i.e. Radiohead), regardless of political orientation. Some conservatives admire lots of things I like which are a bit more opaque, but really despise the people who've made it (i.e. Thom Yorke, Morrissey).
Conversely you can't imagine a Manic Street Preachers fan voting Tory, can you?