Chrome Music Lab - https://musiclab.chromeexperiments.com
A free resource that allows you to create and interact with music. This website offers a myriad of different activities to do and you can even save your work and send. I recommend this website for 3rd grade and up.
A fun way to learn about the instruments of the orchestra. Great way for 3rd grade and up to review!
There are a bunch of interactive music games. Many good for younger students (Pre-K to 2nd grade) on PBS Kids Music.
I recommend the following music games:
Peg's Parade (Pre-K to 1st grade)
Pinka-Perfect Band (K-2)
Spin & Sing (K-2)
Rock Out With Peg and Cat (K-2)
Make Music With Sesame Street Friends (Pre-K to 2nd)
"Month of Musical Missions" -
This website is for grades 2-5.