Rhapsody used to be quite similar to spotify. Their desktop app let you play free music. But lately they've fallen behind and their player UI hasn't changed much for like 5 years. They don't have a Mac app. But if you use windows, Rhapsody comes close to Spotify in terms of features.

I have been wondering the same thing. Learning about Spotify (and finding out it wasn't available in the US) led me to a paid Rhapsody account. However if the UI is better and selection about the same I'd probably jump in a hearbeat.