Isle of Tune is music sequencer where users build compositions visually using houses, roads, plants and cars. Can be used to reinforce a range of musical concepts.

Hookpad is a free web app that simplifies songwriting by helping you choose chords that sound good together and guiding you to write a good melody. It's a musical sketchpad with music theory "built-in" to make it easier and more intuitive to find the sound you're looking for.