In woodwind and brass instruments, the word register usually distinguishes pitch ranges produced using different normal modes of the air column, with higher registers produced by overblowing. Often the timbres of different woodwind instrument registers tend to be markedly different.
However, on the clarinet the notes from (written) G4 or A4 to B4 sometimes are regarded as a separate "throat register", even though both they and the notes from F4 down are produced using the instrument's lowest normal mode; the timbre of the throat notes differs, and the throat register's fingerings also are distinctive, using special keys and not the standard tone holes used for other notes.
The register in which an instrument plays, or in which a part is written, affects the quality of sound or timbre. Register is also used structurally in musical form, with the climax of a piece usually being in the highest register of that piece. Often, serial and other pieces will use fixed register, allowing a pitch class to be expressed through only one pitch.
Vocal registration is a topic of study within vocal pedagogy and is an important subject for students of the art of singing. A register in the human voice is a particular series of tones, produced in the same vibratory pattern of the vocal folds, and possessing the same quality. Registers originate in laryngeal function. They occur because the vocal folds are capable of producing several different vibratory patterns. Each of these vibratory patterns appears within a particular range of pitches and produces certain characteristic sounds. The term register can be somewhat confusing as it encompasses several aspects of the human voice. The term register can be used to refer to any of the following:
Within speech pathology the term vocal register has three constituent elements: a certain vibratory pattern of the vocal folds, a certain series of pitches, and a certain type of sound. Speech pathologists identify four vocal registers based on the physiology of laryngeal function: the vocal fry register, the modal register, the falsetto register, and the whistle register. This view is also adopted by many vocal pedagogists.