The new, revamped MySpace Music promises to be the most significant rollout of a digital-music service since Apple’s iTunes. It enables MySpace users to listen to any song from the catalogs of Universal, SonyBMG, and Warner Music (WMG), which together account for 77% of all U.S. album sales.

There are on-screen ads along with that music, but yes, it will be free. And that includes U2, Jay-Z, Christina Aguilera, Kid Rock and Coldplay.

Visit the pages of major label artists and click on songs to create playlists on your own myspace page made up of those tracks. If listeners really like a particular song, they can buy it with one click and have it routed immediately to iTunes or Windows Media Player via a download service created by Amazon.