Consonance
Literally, sounding together.
Those intervals that enter into the composition of the common chord and its inversions, viz., major and minor 3d and 6th, perfect 4th and 5th, and octave. The major and minor 3d and 6th are called imperfect consonances, being equally consonant whether major or minor. The perfect 4th, 5th, and 8th are called perfect because any alteration of them produces a dissonance; i. e., an interval that requires resolution.
N. B. This definition of consonance applies only to the modern tempered scale. Con sordini (It.) (sor-dee'-nee). With the mute. (I) In piano music, with soft pedal. (2) Instruments of the violin family: a direction to fasten on the bridge a small implement of wood or metal which has the effect of deadening the tone. (3) Brass instruments: a direction to place a coneshaped piece of wood covered with leather in the bell, which has the same effect.