Perhaps I should have tea with my former teacher and ask her what was up with her teaching of playing by the nails.
When you say "playing by the nails" do you mean that the fingernails actually touch they keys? I don't think they ever should (except in glissando
), for several reasons and not just because it would make a distracting clicking sound. If only
the nails made contact, they would slide around on the polished key surfaces like skates on ice. To prevent this, the player would either make the fingers tense up and rigidify more than is good for them, or change the contact angle to tilt the nails out of the way. Such tensing is certainly bad, and while decreasing the angle is sometimes good, doing so only to keep the nails away can't be a good thing. If both
nails and balls of the fingertips touch, the nails will be (somewhat painfully) pushed either up and along the finger (when vertical) or away from it (when slanted). Either way it spoils the tactile feedback. That's why most pianists cut (or bite
) their nails fairly short. In normal playing, then, only the balls of the fingers should touch the keys.
I think both curved and straighter finger positions have their place; the former is more general-purpose and suited to playing powerfully, exploiting the inherent rigidity of the curvature (as in architectural arches), the latter is apparently (as Chang says in his book) better suited to fast passage work, but should not be over-used since it is apt, particularly when playing powerfully, to degenerate into what Heather calls "squashed knuckles" or what my teacher used to liken to "spider legs".
There might be a good pedagogical reasons, but if there are, she didn't really follow through sadly.
Because the straighter position seems
more natural to beginners, I guess it's pedagogically better to "force" them to play curved first, since this habit is easier to acquire when you start than later on. Once the curved habit has firmly established itself, a pupil may be "permitted" to straighten the fingers up a little, when necessary.