One cat we had only had to see me carrying something he couldn't readily identify, and he would assume it to be a musical instrument, and scuttle out of the room. Mind you, he had heard me playing highland pipes and rauschpfeife. A later cat, on the other hand, would happily sit on my knee while I played fiddle, being bounced up and down while I tapped my foot. Nor did he seem to mind the Spanish bagpipes. Our last cat didn't like my son playing the euphonium, but would go into my daughter's room while she played along to 80s pop on the drumkit. He would sit alongside, purring. She claims that his favourites were the Pet Shop Boys. Hmmmm.....
The cat stroking the guitar strings in topsie's video link above reminds me of a kitten we had when I was a youth. I taught him to pluck the strings on a ukelele. But, being a cat, he couldn't be arsed practising, so never progressed beyond 'My Dog Has Fleas".

John Kelly.