My favorite classical music for young children is Saint-Saens "Carnival Of The Animals". It is made up of fourteen short songs, each with a name of an animal and one called "pianists" This music is fun and imaginative. The composer uses instruments to imitate animal sounds, like the deep, rich cello for the "Swan". Many versions of this piece are available. My favorite one comes with a beautiful book with commentary by Barrie Carson Turner and illustrations by Sue Williams, published by Henry Holt and Company. Each piece has it's own page with gorgeous pictures and a little explanation about the instruments used and the sounds the animals make. I highly recommend this book and CD. I have used it for years and the kids always love moving and playing along with this music!