Definify.com
Webster 1913 Edition
Keynote
Key′noteˊ
,Noun.
1.
(Mus.)
The tonic or first tone of the scale in which a piece or passage is written; the fundamental tone of the chord, to which all the modulations of the piece are referred; – called also
key tone
. 2.
The fundamental fact or idea; that which gives the key;
as, the
. keynote
of a policy or a sermon