It's so refreshing and makes me smile when I hear my sweet E. who is 3, humming along to Peer Gynt - Morning by Edvard Grieg.
Here's a visual for you! This is one of my favorite classical songs, and every time I listen to it, this YouTube video absolutely captures what visions I have in my head! It is purely relaxing!
Enjoy!
http://youtu.be/gH1JMdWpJ54