Okay, i'm no expert, i don't know how the play. But wanted to learn it a while ago.
As i think i could be a user, this is what you "could" keep in mind:
What i did was (i didn't have a piano and that's expensive), i bought a piano keyboard. (it's like a piano but with notes instead of buttons and it runs on batteries :-P).
All that i learned, was the start of the fûr elise while watching youtube videos. I know about the 30 first notes or so and that's where my expertise ends.
My brother has a piano, what i did then was put a tablet on top of it (not much space on it) and imitate a "virtual piano" app. I could imitate some some because of this.
Some things you should know:
The idea of this project is great, but a lot of people who don't own a piano. So your audiance is already "limited". Suggest alternatives like a cheap piano keyboard for the ones who don't have one. Just to get them started.
Second thing, not much people have place to put a monitor on top of their piano. A tablet is about the max you can get on top of ours.
You could start looking into Raspberry Pi and small screens to adjust this.
Third thing, you are showing notes and in the start, people don't know where the notes are, you could show piano buttons /places instead.
Fourth thing, you're video isn't inspiring. If you look at the top kickstarter campaigns... You'll see a lot of different things then you're video. Watch these for inspiration:
http://www.kickstarter.com/projects/556341540/pressy-the-alm...
http://www.kickstarter.com/projects/danshapiro/robot-turtles...
Because no matter what people say, kickstarter is work.. And making a video is your ad to the outside world.
I haven't seen any idea that got into the media, with a bad video. If you want to know how important it is, read this: http://www.danshapiro.com/blog/2013/09/robot-turtles-midmort...
You need referrals, kickstarter is only a place where they can give you money.
I'm sorry if i sound rude, i don't have much time right now and just wanted to give you immediate feedback on my perception of things. I understand how "miserable" it can feel if "kickstarter" doesn't seem to work.
Get into some music/piano communities / forums / .. online. I have read on a lot of places that those could be your audiance.
Going out on other places for feedback, inspiration, ... is a sign you want it. But besides wanting it, there's also a lot of work into media / marketing.
I wish you the best and if you could address the above things. That's my sign to support you as a non-piano owner :), but perhaps i'm not your audiance also.
For you to decide.
PS. Wrote the comment fast and i'm not a native english speaker /writer