The first thought I had had two parts: a playground and a piano. The playground element didn't operate well, so I chose to delete it, and the piano feature at the time didn't have a recording capability or all of the keys on a real piano, so only very simple tunes could be created.
The playground mode where colours and shapes would burst out as a reaction to noise and snapping of your fingers. Through many experimentation, I decided to just push the piano feature, and include a recording button so users, could save their music master pieces. Users can use the keypad or the keyboard to play the piano.