Machine Learning Playground - Breathtaking visuals for learning ML techniques.

Flowkey - The easiest way to learn piano with your iPhone or iPad

Amazon Machine Learning - Machine learning made easy for developers of any skill level

Yousician - Learn to play music at home, at your own pace

ZILLIN - Create large accurate training data sets fast

Melodics - Melodics is a desktop app that teaches you to play MIDI keyboards, pad controllers, and drums.