I'm sitting here UNTZing away, my neighbors probably want to kill me but my dog is laying on my bed snoring away. However if hes in the back yard and someone starts up the lawnmore or people light off fireworks he spooks. My cat is the same. I've had birds at multiple points in my life and they without a doubt have some sort of rhythmic understanding.
I assume the dog is accustomed to you playing music and well, who doesn't hate the sound of lawnmowers. Not too long ago I cheered up my lizard with some piano playing. No bullshit he was brown (which indicates stress) and morphed to green.
Do animals have the intellectual capacity to appreciate? "I like this", yes but appreciation is high level thinking.