iPad Music Software: Chromatone Lite (App Store link) is a free iPad app that lets you try out hexagonal keyboards.

According to developers:

MUTO Music Method (Chromatic system), which use Chromatone and 3 scores, let us eliminate unimportant symbols like ? or? and exclude the distinguishment between black key and white key, so we can deal with all 12 keys easier.

The result is all 12 keys of finger-lead and form like chord and scale is identified, so the quantity of practicing will decrease to 1/12. You can perform and memorize the theory 12 times speedy up than before.

Alternate keyboard layouts have long been esoteric. The flexibility of touchscreens like the iPad are making it possible to bring these once-experimental controllers to the mainstream – where they may be given a chance to live or die on their merits.

via PalmSound