How are people playing music so well is there a trick to it?

[TheMightyMollusk]

*shrugs* given that you agreed you'd never play any music that you don't personally own, on pain of having your entire account deleted... what's the point of the player piano program?

That's the devs covering their bases in case someone tries to sue them over "stealing" copyrighted music. It'll never be enforced unless someone makes a legal issue of it.