zipping up a jacket is really hard to do, and requires very precise movements and coordination between hands.
playing mozart is much more forgiving in terms of the number of different motions you have to make in different directions, the amount of pressure to apply, and even the black keys are much bigger than large sized zipper tongues.
Pretty much. The issue with zippers is that the fabric moves about in unpredictable ways. Piano playing was just movement programs. Zipping required (surprisingly) fast feedback. Also, gripping is somewhat tough compared to pressing.
