Initially, Music Beta will support storing of up to 20,000 songs for free, and Google has suggested that the service will offer a "generous" free package even after Beta. At launch the service is only available through invitation to US residents only. It does not currently support buying music, only uploading a user's own music for streaming purposes. Music Beta also allows for automatic caching for offline play on mobile devices.
According to the official Google blog, users "can use a feature called Instant Mix to create a playlist of songs that go well together." Music imported from iTunes will retain playlists as well.
Music Beta was first hinted at at the 2010 I/O Conference, where Google Senior Vice-President of Social Vic Gundotra showed a "Music" section of the Android Market that would allow users to download music through the market. In June 2010, a user discovered a logo that said "Google Music" on Google's servers, but it was later deleted.
Music purchasing features were absent when Music Beta launched in 2011. Jamie Rosenberg, the overseer of digital content and strategy for Google, told All Things Digital that "a couple of the major labels were less focused on the innovative vision that we put forward, and more interested in an unreasonable and unsustainable set of business terms," which led Google to make Music Beta a standalone streaming service. (Reference from : wikipedia.org).
