Sampulator - Make (and record) beats on your keyboard
ChordIQ - Learn notes, chords, sight reading, perfect pitch and more.
Tinkersynth - Create and purchase unique generative art
muted.io - A magical collection of interactive music theory tools & visual reference pages for musicians and music producers
Splice Beat Maker - Make and share beats in your browser
7Pad Scales and chords - Music instrument and assistant for playing scales and chords.