In music, duration is an amount of time or how long or short a note, phrase, section, or composition lasts. "Duration is the length of time a pitch, or tone, is sounded." A note may last less than a second, while a symphony may last more than an hour. One of the fundamental features of rhythm, or encompassing rhythm, duration is also central to meter and musical form. Release plays an important part in determining the timbre of a musical instrument and is affected by articulation.
The concept of duration can be further broken down into those of beat and meter, where beat is seen as (usually, but certainly not always) a 'constant', and rhythm being longer, shorter or the same length as the beat. In serial music the beginning of a note may be considered, or its duration may be (for example, is a 6 the note which begins at the sixth beat, or which lasts six beats?).
