It's not music but I have an alarm clock with 'nature sounds' that includes an owl hooting. Cami cannot stand it when she hears that and runs to hide. I had to change the sounds on it so it would quit scaring her.

Jack hates riding in the car and meows the whole time. I've found that some easy listening, particularly Air Supply, and alot of country music, particularly Louise Mandrell, seems to calm him down. I think he likes the base and deep voiced singing sounds. When we play those for him he seems to calm down, lays down in his carrier, and only meows very softly occasionally. If the wrong song comes on he'll stand up and start this horrible screaming meowing tirade until we get the song changed.