A short summary of Creative Commons licenses and their uses for music in video:
CC-BY: can be used in video, as long as you attribute the original author
CC-SA: can be used in video, as long as you license the video under the same license
CC-NC: can be used in video, as long as it is only for non-commercial purposes (which can be tricky, as your video could be considered a promotional video for RPi by some; I guess CC-NC is also incompatible if you receive money from youtube ads)
CC-ND: can not
be used in video, or indeed any other derivative work
They usually come in combinations (like CC-BY-SA, CC-BY-NC, CC-BY-NC-SA, etc.), with the expected meanings.
You can find (and probably have found) all this info on wikipedia too, but I thought I'd post it here as well.
As another music suggestion: you can never go wrong with a Kevin MacLeod
piece; his music is used all over youtube for background music (and is CC-BY).