Hi there,
For now our music shield was design basis Arduino 0023 IDE or libraries.
So that version is not allow to realize the function what you said, but in Arduino 1.0 it is change.
So play multiple files would be possible, if we design new one in hardware.
Anyway, can you tell us why you want to play like this, for example?
Or any reason to let us know, how to use, which situation you’d want to play with?
Give us more reason, that would more helpful for our new product.
Best regards,
Yuri