Google officially release Google Music services now.
Users can upload their own music files or shop millions of songs in Android Market. Google music stores 20,000 songs for free in addition to the purchase. Listen on the web or Android mobile devices without the hassle of wires or syncing.
Google music adds social network feature. Users can share the music with their Google+ friends after purchasing. Your friends are able to the entire song instead of 90s trial.
Other than agreement with the music companies, Google also signed agreement with T-Mobile, so that users can buy songs with the mobile expense.