Our latest addition (1.5 year old Annette-Lucile who is a little orange kitten) has had her own CD since we found her 15 months ago. Not a clue as to why she likes it so much (Dusty Trails), but she runs about the living room making chirping noises while it's playing.
I picked it out for her when she was 3 months old, telling her it was hers, as it was the only chick music (other than George Michaels "Faith") we had on hand.
She also likes a few songs off Rebecca Pidgeon's "The Raven".
The only Beatles recording we own is "Revolver", plus the solo work "All Things Must Pass" and a few Lennon LP's.