We had so much fun doing activities centered around Peter and the Wolf that I decided to try out The Carnival of the Animals by Camille Saint-Saens with L.
It is a classical piece with fourteen short movements each musically depicting a different animal.
If you haven't heard of it before I would really recommend checking it out. The pieces are a brilliant introduction to classical music as you can really hear the different characteristics of each animal. For example the clarinet plays the cuckoo sound of a cuckoo and the violin the "eehaah" of the donkey. The link above has a detailed description of each movement.
For L's first introduction I told her the name of the piece and that it was about different animals. As we listened to each one we acted out the animal and talked about which instruments represented each animal.
L insists on wearing her feather crown every time : )