I wanted to make a music game. There a lots of them in which you need to play the music, like Guitar Hero or Taiko no Tatsujin, but I wanted to experiment with a game about making music, not just playing it.
Will it be fun? I don't know. Maybe there's a reason why most music games are about playing music, following the rhythm or dancing. So that's my plan B!
Another thing to take into account, is that I have very little time to develop this game, since I started the challenge mid-month, and I'll also need a few days off for recovering from a medical procedure I have scheduled this week.