Earlier quoted context omitted.
The vast majority of software jobs do not need performance artist skills. Most of the pressure is deadline pressure, not "stage" pressure.
Say that you own an auto repair facility. You have 10 mechanics who have applied, and all ten have previous experience on their resume. How would you interview them, so as to choose the best candidate the first time?
For the music teacher I would have them record the piece, and send in the best take. I wouldn't demand they get on stage and play the piece.