I guess I've interepted the problem wrong. I took it to be something along the lines of you need X elements to create one Y. The order of the elements effect the a Y. So ABC and ACB, etc would all be unique Y's in a 3X=Y situation. This scenario would yield !X-!(X-3) possibilites. I assumed you couldnt reuse samples, but if you can then the number of possibilites would be X^3. So if you used the alphabet as your X pool, then you would have either !26-!23 possibilites or 26^3 possibilities depending on the rules.
Clarify the rules of creation for one mario soundtrack.