Ableton created some fantastic free online platform to learn the basics (and more) about music. There are over a hundred lessons available. In these lessons, you'll learn the basics of music making. No prior experience or equipment is required; you'll do everything right in your browser. They use great new technology to let you create music online.
Check it out on: https://learningmusic.ableton.com/
ALso check out our review of Learning Synths online of Ableton here: http://www.hrscourses.com/index.php/blog/121-ableton-learning-synths-online