My main passion is Heavy Metal. As a consumer, I use Twitter to keep up to date with tours, releases, news by following bands and music media. I use it to interact with bands.
I also have a band which has a Twitter account which is used to keep people up to date as mentioned above, and I have a music blog twitter account which I use to review gigs etc...
I have a pretty good Metal Twitter list here if anyone is interested: https://twitter.com/ColinHugh/lists/metal-news