So, today i was just browsing youtube, when i found one video...
And in that video there was a site, with virtual piano in it...
https://virtualpiano.net/
And... THIS IS TOO OBVIOUS, IT'S THE SAME PIANO.
Even many musical sheets are the same, as the site.
But... come on, why didn't you just added more sheets from that site?
Like mortal kombat theme...

BTW, Why won't you just make those sheets - a client stuff, so anyone would be able to add their own sheets, to play music? (Because it's boring to write every note on the paper.)