May I register with ©copyright my songs made mixed with just apple loops or must be copyleft, creative commons, royalty free, etc...? I'm starting to use GarageBand for making music, and I have several songs of my own; but I find xtremly funny mixing loops, so, I have another ones that are only loops mixes. 

I know that they are royalty free if you mix the loops, I've read a lot, and I didn't find the answer to my question in the web. (February 2016)

I want to sell the songs, but I don't know if I can put my ©Copyright stamp in the only loop ones. 

Can somebody help me understand the licensing terms?
Royalty free means you can release music that incorporates the loops without paying or crediting anyone. The only thing you can't do is sell the loops separately.