e music we must make all the sounds mean something, just as
it is no use to pretend to speak unless the sounds we make with our lips
mean something, that is unless they form reasoned phrases and
sentences."

Here nothing is left vague. Matthay shows clearly how all musical Form
and Shape imply Movement and Progression: the movement of a phrase
toward its cadence; the movement of a group of notes toward a beat or
pulse ahead, or the movement of a whole piece toward its climax, etc.
This original view of his regarding form, which he has advocated for
the last twenty years, is now being accepted generally by the more
up-to-date of the English theorists and teachers.

In regard to key mechanism and what must be done to produce all
varieties of touch and tone, Matthay has made exhaustive studies. He
says (_First Principles of Piano Playing_): "The two chief rules of
technic, as regards the key, are, therefore: Always feel how much the
key resists you: feel how much the key _wants_ for every note. Second,
Always listen for the moment each sound begins, so that you may learn to
direct your effort to the sound only, and not to the key bed. You must
never hit a key down, nor hit _at_ it. The finger-tip may fall on the
key, and in gently reaching the key you may follow up such fall by
acting against the key. This action against the key must be for the sole
purpose of making it move--in one of the many ways which each give us
quite a different kind of sound. And you must always direct such action
to the point in key descent where the sound begins."

I quote also this little summary from the same work:

"(a) It is only by making the hammer-end of the key move that you can
make a sound. (b) The swifter the movement the louder the sound. (c)
The more gradual this swiftness is obtained the more beautiful the
quality of sound. (d) For brilliant tone you may hit the string by means
of the key, but do not, by mistake, hit the key instead. (e) You must
'aim' the key to the _beginning_ of each sound, because the hammer falls
off the string as you hear that beginning, and it is too late then to
influence the sound except its continuance. (f) It is wrong to squeeze
the key beds, because it prevents tone, impairs musical result, impedes
agility, and is, besides, fatiguing. (g) You must feel the 'giving way
point' of the key, so that you may be able to tell how much force is
required for each note. Never, therefore, really hit the keys."