If you don’t mind listening to some chatter between songs, check out music-oriented podcasts available for free on iTunes. You can also follow the Free iTunes Downloads blog, which updates every time a new item appears. No-cost items in the Free On iTunes section are usually available for around a week, so keep checking the page for updates. You will need an iTunes account to download anything from the iTunes Store.
To download a free item, just click the little gray Free button.