Replace "tap" with "click" in your post. How is the iPad better than doing the same things with the mouse? I don't dispute that a very nice app could be created, but I question whether the iPad itself enables any of those things.<p>Further, a finger is a very imprecise input device. For music, precision is very important. Even a mouse is not precise enough for lots of things I do when I use DAW software.<p>Music notation is one place where I think pen-based input would be useful. It's precise and the input language is tightly scoped enough that the recognition problem is solvable. There's also no existing system that lets you input musical notes in any faster way. Recording-based apps (midi or otherwise) are always at the mercy of the performer. And unless you're superhuman (I'm not), you have to spend a long time quantizing and correcting the transcribed rhythm. It's real bummer. I would much rather scrawl the notes and know that they'll be nicely typeset out the other end.