Simple answer, from Magix Music Maker version 17 to up Audio Pro License is needed if music is to be used in commercial projects. If you have bought Audio Pro license for MMM 17 in that case first read the license terms. Or you can buy from:

http://www.catooh.com/uk/sys/id/Katalog/area/mediaDetails/item_id/225762/

Additional: as far as I know, samples could not be used in commercial work.