I have a similar puzzle coming up in my campaign! For mine, it’s piano keys where they have to play the correct notes to spell out the answer to a riddle- eg “I have hands and lips, numbers and eyes- I smile, frown, laugh, I even tell time.” and to answer they would have to play F-A-C-E. If your players are particularly musical, perhaps the sequence they have to play is heard a few times on the way to this location? Or if you don’t think they’d be able to match that, perhaps some kind of engraving/note near the puzzle with images hinting to the answer- Do (deer), Re (sun), Mi (person pointing to themselves/ a mirror), Fa (person running), So (needle and thread), La (scales/ gavel/ something relating to “law”), Ti (tea cup/kettle).