KEY
, in Music, is a certain sundamental note, or tone, to which the whole piece, be it concerto, sonata, cantata, &c, is accommodated; and with which it usually begins, but always ends.
Keys denote also, in an organ, barpsichord, &c, the pieces of wood or ivory which are struck by the fingers, in playing upon the instrument.
Keystone, the middle voussoir, or the arch stone in the top, or immediately over the centre of an arch.— The length of the keystone, or thickness of the archivolt at top, is allowed by the best architects, to be about the 15th or 16th part of the span.
