As a child, mid 80s, would always watch a certain film (think it was something iconic, like the snowman). And there was always a 5 minute animation that came on before it.
It was about a woman with a cat (white, I think) that her husband got her. She was a piano teacher possibly and the cat would let her know if she played the wrong note. It has a sad ending, think the cat dies.
it just popped into my head before I fell asleep the other night and can't for the life of me remember what it was!