Velocity
Velocity depends more upon natural elasticity than strength. Some people seem to be born with the ability to play rapidly. It is always a matter of the fingers, but is more a matter of the brain. Some people have the ability to think very rapidly, and when these people have good supple hands they seem to be able to play rapidly with comparatively little study. When you fail to get velocity at first, do not hesitate to lay the piece aside for several weeks, months or years. Then you will doubtless find that the matter of velocity will not trouble you. Too much study upon a piece that fails for the time being to respond to earnest effort is often a bad thing. Be a little patient. It will all come out right in the end. If you fuss and fume for immediate results you may be sadly disappointed.