A trill is one of the most common melodic ornaments (alongside mordents and grace notes): the rapid, repeated alternation of the main note with the adjacent one above (a second higher). It is marked by the letters “tr” over the note. Performed with mastery, a trill sounds brilliant and sparkling, as if the sound “quivers” from inner energy.
Trills especially flourished in the music of the Baroque and Classical eras, where the ornamentation of a melody was an art in itself. A long trill at the end of a concerto cadenza became the traditional “signal” for the close of the solo episode. The trill sounds on all instruments and in the voice: from a singer's brilliant coloratura to the birdlike chirping of a flute. It is a small but vivid detail that demands virtuosity and lends music elegance, festiveness, and vital energy.
