Epitonic top mp3 free and legal downloads from a huge variety of music particularly strong on indie and electronic with a large 20th century composers section. In addition to the top download list if you browse the categories every band has at least one free sample mp3. Even better is the Epitonic Radio player which lets you select from 50 music categories and make a streaming playlist of 20-500 tracks or stream entire albums or even select a band and automatically generate a similar band playlist. I can't think of a better way to discover new music.

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Even more MP3s from the Hype Machine archive of blog audio