I’ve come across some new (old) links to Royalty Free Soundtrack, Audio beds, music and more! Adobe offers some free sounds for Audition users. There are hundreds of sounds! Be sure to check out the user agreement before downloading these.
Youtube has been offering free sounds and sound effects for awhile now, you may have missed it in your ‘Creators Studio’ section of your youtube interface. Log in and check it out!
Full list of Music and Sound FX sites:
Youtube Audio Library
Adobe Audition Downloads
Final Cut Pro X Content v1.0
Audio Library – No Copyright Music
David Cutter (Casey Neistat – Vlog Music)