Ritardando (Italian for “slowing down,” marked rit.) is an instruction for a gradual, smooth slowing of the tempo. It is one of the most important means of agogics — the flexible “breathing” of tempo that brings mechanically even playing to life.
Ritardando is most often used at the end of a work, section, or phrase to gently prepare the ending, to “land” the motion, to give a sense of calm or significance. It also underscores emotional climaxes. Related terms are rallentando (rall., a gradual slowing down) and ritenuto (a sudden holding back). The opposite of ritardando is accelerando (speeding up). Skilful, natural ritardando is a mark of musical taste; excessive ritardando makes a performance sluggish. It is a subtle instrument with which the performer controls the very flow of musical time.
