www.musictheory.net
http://www.creatingmusic.com/
http://www.isleoftune.com/
https://musescore.org/en
http://www.nyphilkids.org/
http://pbskids.org/chuck/index.html#/jazz
http://www.pearldrumrudiments.com/
http://www.themusicinteractive.com/
http://www.themusicinteractive.com/kbe/Chromebook/index.html