Rays is a musical instrument that plays chords by the touch of the display. The touch also makes rays and other geometric shapes show on the display.

Each page has its keynote(tonic) at the center of the display. Chords that are meant to work well with the keynote(diatonic chords) are placed around to make it easier for beginners to play music-like sounds.

You can change the keynote by touching the arrows shown below. The idea of this instrument is to perform as the so-called “ano-gakki” (“that instrument”) which appears in one of the contributions to “nikoniko douga”, a promotion movie of song “Innocence” a vocaloid Miku Hatsune sings.

http://appshopper.com/music/rayz-type-c