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.
- The tonic of a musical key.
- A prime underlying element or theme: "The keynote of the revolution settlement was personal freedom under the law” ( G.M. Trevelyan).
- To give or set the keynote of.
- Informal To give a keynote address at: keynoted the press luncheon.