What's the catch? Simply attribute the writer of the piece in the credits. That's it!
Incompetech has a range of different styles of music available, from African to disco to classical, for use for free under the Creative Commons. Although there is not a huge list of songs in each category, and they are mostly songs/pieces original to Kevin McLeod, they are there for use in any media form for free.
For learners, Incompetech can be viewed as a Learning Resource which can help learners successfully complete an ICT-based Learning Task (Oliver, 1999). This music is simple to download and can be added to video clips (that may be uploaded to YouTube or TeacherTube), Powerpoints presentations, Drama pieces (including mime), or just for general classroom purposes (e.g. 'quiet working' music, as back-up music for a parade item etc.).
You don't have to join, the music is free to download, it can be saved to your music library on your computer... The only thing learners need to be aware of is that they must acknowledge the writer/composer of the piece.
I downloaded a classical piece entitled 'Danse Macabre', which, being classical, is acknowledged to have been written by Saint Saens in 1874. It was quite a long piece, however it only took a couple of minutes to downlaod it into iTunes.
Not a bad tool/website to keep bookmarked!
Oliver, R. (1999). Exploring strategies for online teaching and learning. Distance Education, 20(2), 240-254.
Available from http://www.learningdesigns.uow.edu.au/project/learn_design.htm