I have music maker too, all the soundpools have no copyright on them and are available to with as you please. Meaning selling your creations with their samples is legal. If you're uncertain of other samples that you have attained, you can right click on the file and go to properties, there is where you would see the copyright. Sometimes you might run into one with a copyright on it but most times you wont. I'm look forward to hearing your Music Maker creations.
P.S. you might want to read the legal part for Music Maker Jam, I haven't gotten that app yet, if I am correct at saying it is a free cell phone app. If so, then an unpaid for app might have some copyright ties to its sounds. Not sure, but definitely something to look into.
