There are a lot of music services that provide tons of free streaming music (SoundCloud, MixCloud, Deezer). These services are used by the lables and artistis to publish their music. Almost all of them in order to listen you have to create account.
The MusicSelector taps into their API and provides to all of the people free service for listening music.
The Music Selector also allows the users to create their accounts or login with the popular services. They can just listen music, or manage their accounts on the services.
The Music Selector can also be used for promotions and featuring artists and as a mini social network for music fans.