Motive
The shortest recognisable unit of pitch or rhythm that can be transformed
Related
A motive is the shortest unit in music that can still be recognised: a few notes, a rhythmic figure, or a combination of both. It need not be a complete melody; often it is only two or three notes, yet it has a contour and a character of its own. The opening of Beethoven's Fifth Symphony — three short notes and one long, falling by a third — is the famous example: short enough to grasp at once, strong enough to carry an entire symphony.
A motive matters because it can be transformed. It may be transposed, augmented, diminished, played backwards or inverted; it may keep its rhythm and change its pitches, or keep its pitches and change its rhythm; it may also be broken up so that only one cell survives. A composer can send the same motive through different voices, keys and registers, and listeners need not recognise every return to feel that the whole work grows from one source. A motive is like a seed: not the plant itself, but the thing that decides what the plant can become.
The common misconception is to treat a motive as a short melody and assume that a longer, more complete shape is more important. In fact a motive is useful precisely because it is short: change one note of a long tune and it collapses, while a motive can lose several notes and still be recognised. Nor must a motive repeat unchanged; it usually returns in new clothes, leaving only a recognisable frame. Whether something is a motive depends on whether it keeps its identity through change, not on how often it is repeated.
Sources
- 动机的定义、识别与变形手法，参 The New Grove Dictionary of Music and Musicians, "Motif"；本文为原创表述
Used for fact-checking only; all prose is original.