You save teams of sky divers from hard landings by nailing chords in the Ripchord arcade. You exercise pitch and rhythm in the practice room under the attentive eye of a tutor. In the performance hall, you play serious music with other performers. Two hands, of course. Musical purists have already somberly advised me that teaching music by machine is bound to end badly.
Nothing can substitute for a really good human teacher.
A machine will tolerate bad habits and slovenly technique. I'm sure they're right. The same goes for poetry readings about performing bananas. Our single best piece of educational hardware has turned out to be one she discovered for herself. You get the printout on a little peel-off sticker.