A music service application that can be run on a wireless mobile device enables audio data to be progressively downloaded from a remote server and also enables locally stored data to be played efficiently. Audio content that is relevant to a user is identified and downloaded to the user's mobile device, in some cases with minimal or no effort by the user. Continuous play features ensure that the user can experience an uninterrupted music experience, both in online and offline modes. Social features such as playlists and preferences of other users are leveraged, to provide users with popular music that is relevant to their interests.