In Adventurebackpacks which this mod is obviously a port of, the Rainbow Backpack played the nyan cat song when sprinting (or when eating a golden apple, i dont remember anymore, but it would make more sense when sprinting since the note particles).

PLEASE I BEG YOU, ADD IT BACK IN
i need it so much, it feels so unstatsifiying running with note particles without hearing that song.
please please !!!