Yes, but using music theory, one could probably discount many of those that wouldn't be considered "music". You generally don't go back and forth between 4x whole and 1/128 notes repeatedly, and you generally don't go back and forth between the highest and lowest note in the octave repeatedly. You could probably stick to anythign between hole notes and and 1/16 notes, and get the majority of the song. Also, note that as far as copyright goes, changing the pitch of a song to a different key would still be considered the same song, as would playing the song at double speed. There may be a lot of combinations of notes, but not nearly as many would be musically distinct, and also considered music.