Your .spc doesn't even run on my end with the more modern players (and real hardware for that matter) because of one major reason: you failed to set up the instruments. Therefore, all of the instrument pointers are pointing to $FFFF in SPC700 RAM, which is essentially nothing.
Update: Well... maybe not exactly nothing. The player I use by default, Game Music Box, fails to emulate wrap-around to $0000 in SPC700 RAM properly. But it explains exactly why only one sample is playing.