No, Really
One great feature of the site Last.fm is that many free tracks are available there. One discovery I made there a few months back was Tennessee musician Hannah Sheehan who goes by the moniker "No Really" (no, really!). Fun times abound with a name like that.
No Really has a bunch of free songs on Last.fm, all of which are also available on her website, along with a link to donate, which is totally worth it if only for the smirk-worthiness of getting your credit card bill and seeing the words "no really" on it.