What are some alternatives?
Spotify - Sweeden-based Spotify started in 2006 as a way for users to stream music directly to their device while providing royalties to the artist.
Hermes - Pandora Client for OS X
Last.fm - The world's largest online music service. Listen online, find out more about your favourite artists, and get music recommendations, only at Last.fm
Pithos - pithos is a daemon which provides an S3-compatible frontend for storing files in a Cassandra cluster.
Google Play Music - Free radio for everything you do. Store 50,000 tracks from your personal collection. Subscribe for on-demand access to 40 million songs and offline listening.
Elpis - Elpis is a free and open source Pandora client for Microsoft Windows.