Bandcamp
Bandcamp focuses on discovering and buying independent music.
What it does
Bandcamp lets musicians publish work that listeners can purchase.
When to use it
To support an independent artist, listen through an album page and read its notes.
Visit Bandcamp official site
A Soft Murmur
A Soft Murmur focuses on mixing rain and other ambient sounds.
Audius
Audius focuses on artist-uploaded and shared original music.
Brain.fm
Brain.fm focuses on music arranged around work and rest contexts.