Good question. I think that it could be possible to call a bell as an instrument. It does make a lot of sound, so it could be counted as a musical instrument for some people.

(As soon as she said it, she gets a tug on her line and proceeds to reel it back to her. She was worried that the flute might be out of reach for all of them as she nervously gets the fishing line to come back to her.)

Well. I think that I got something but I have no idea what it could be.