There's lots to do on this kids' orchestra site, including:

Instrument Room where you can learn about the orchestra instruments and hear them play.  Musicians Lounge where you can "meet" some of the musicians in the orchestra. Orchestration Station, where you can select which instruments you want to play a piece, and hear the results.
Some of the instrument profiles include quotes from philharmonic musicians about what they think about when playing the instrument. The Game Room has some fun and clever games too.

 

Classical music's great composers come to life through music and stories.  Choose from Composer Timeline, Musical Dictionary, Composer Time Machine, Note Name Game, Compose Your Own Music, and much more.  The site has many interactive games to help you learn about rhythm, composers, the orchestra, and careers in music.