Just found this San Francisco Symphony site for kids. It explains music, instruments, and has a “composerizer” for kids to “compose” music on their own (and hear it played) and a “performalator” with a keyboard they play by clicking on keys with the mouse (includes simple color-coded tunes). A really fun and educational site to teach kids about music.
http://www.sfskids.com/templates/home.asp?pageid=1
Susan
Thats a neat tip, Susan. 
I can certainly see some kids I know putting this to use as an exploration. I like their idea of each measure being “a house” and the notes being the rooms found in each house. Thanks!
Jef
Thanks Susan! This is really neat! I have passed it on to the Children’s librarian as an added link on the childrens website on our library website.
I played with it quite a bit and even composed a tune.
Thanks again for posting this!
MarkB