Music effects your moods, it can make you feel happy, sad, motivated or bring up old memories. I think this applies to animals too
I've noticed my pets reacting to certain types of music and it's gotten me really interested to see if anyone elses pets, or animals they've seen, react to, love or hate music.
The young boy next door to me is a fantastic piano player, i have the most lovely renditions of mozart and vivaldi filtering through my windows when he practices. I noticed my cat disappers when he plays. I thought she was scared but i found that when he starts playing, she sits at the fence nearest the point where the piano is on the other side, leans against the fence closes her eyes and purrs, she'll sit there only as long as he's playing.
It was lovely
Apparently, cows like trombones and jazz, love this video: