Garageband Loops in Indie Game Apps?
Apple has a support document describing the license:

The GarageBand software license agreement says:
&quot;GarageBand Software. You may use the Apple and third party audio loop content (Audio Content), contained in or otherwise included with the Apple Software, on a royalty-free basis, to create your own original music compositions or audio projects. You may broadcast and/or distribute your own music compositions or audio projects that were created using the Audio Content, however, individual audio loops may not be commercially or otherwise distributed on a standalone basis, nor may they be repackaged in whole or in part as audio samples, sound effects or music beds.&quot;
So don't worry, you can make commercial music with GarageBand, you just can't distribute the loops as loops.