SoundBrush is a US $1.99 iPad app that lets you create original compositions by swiping your finger across the iPad screen. The description sounded a bit odd, but I had fun playing with SoundBrush and discovering what it could do.
You can have a total of 4 instrumental lines -- piano, strings, flute and synth, and it appears the app selects proper harmonies when you lay your tracks down. I was surprised how good my little compositions sounded, although I wasn't quite ready for a concert.
The app lets you hear the notes as you draw them, and you can super-impose a grid to show you the notes you are drawing. You can delete anything you have written with a double tap, so you can actually edit the music you create. The canvas scrolls, so
