\To*nal"i*ty\, n. [Cf. F. tonalit['e].] (Mus.)
The principle of key in music; the character which a
composition has by virtue of the key in which it is written,
or through the family relationship of all its tones and
chords to the keynote, or tonic, of the whole.

      The predominance of the tonic as the link which
      connects all the tones of a piece, we may, with
      F['e]tis, term the principle of tonality. --Helmholtz.