Known issue where the instruments soft lock progress.
Quit out of game. Go to save files, 'save0', scroll to bottom and add
"s objectXX instrumentY:1"
X: is your next object number (Ex: 10)
Y: the next instrument number (Ex: 3)
I've had the same issue, the "powering up" sfx loops and softlocks. I've approached instruments from different angles and had better luck. Stuck at the Catfish currently with no solution.
Went back and tried again. I approached the cello from behind and it worked.
Same issue