cadenza

In music, an unaccompanied exhibition passage in the style of an improvisation, inserted by the soloist at the climax of a concerto movement.

The practice of improvising a cadenza largely ceased around 1780, composers thereafter supplying their own in written form. Recently, however, the practice of the interpreter composing a cadenza has re-emerged, with Stockhausen writing new cadenzas for Haydn and Mozart and Nigel Kennedy recording Beethoven's 1805 Violin Concerto with a cadenza of his own devising.