Non-human's music preference?

[Druidus]

Does anyone else's pets like music? My dog (part German Shepherd, part Rottweiler, part husky, part wolf), Shadow, loves classical music. But only certain composers. She likes Vivaldi, Mozart, and especially Beethoven, but not Wagner, or Chopin. She, like me, likes the fast, active pieces better, but still likes the slow ones, at times. I know this because depending on what I put on she howls. I put on Beethoven, instantly, she's up howling along with the music! Wagner, however, and she just stares angrily at me, and barks every now and then, until I change it. You guys have anything like that?

Also, what is the purpose of music appreciation, in humans, and non-humans? What benefit does it hold?