Metre.

(1) A synonym for Time signature as in ‘6/8 metre’.

(2) More generally, the temporal hierarchy of subdivisions, beats and bars that is maintained by performers and inferred by listeners which functions as a dynamic temporal framework for the production and comprehension of musical durations. In this sense, metre is more an aspect of the behaviour of performers and listeners than an aspect of the music itself.

Metres may be categorized as duple or triple (according to whether the Beat (i) or Pulse is organized in twos or threes) and as simple or compound (whether those beats are subdivided into duplets or triplets). The four basic metric categories are shown in Table 1.

Note that compound metres are ‘compounded’ as a result of the binary orthography of Western durational notation; in order to use a standard note form for the ternary subdivision, one must use a dotted value for the beats themselves.

The basic metric categories reflect the hierarchic structure of metre, as each defines the organization of three temporal levels – subdivisions, beats and bars. There may also be additional subordinate and super-ordinate levels of metric structure (see Rhythm, §I, 4). While the notated time signature usually corresponds to the perceived metre, at times it does not. For example, in the Scherzo of Beethoven’s Ninth Symphony the notated measures correspond to beats and subdivisions, but not to the perceived bar; here a simple triple time signature is used as a means of notating an extremely rapid compound duple metre (ex.1).

Metre is usually stable over the course of a piece, but it may change, either explicitly through a change of time signature or other marking (as in the ‘ritmo di tre battute’ of the aforementioned Scherzo), or through a regular patterning of durations, sforzandi and articulations which force a shifted sense of metre contrary to the indicated time signature.

More complex metres are also possible. In the basic metres the articulations on every level are equally spaced, but in both Western and non-Western music one finds metric patterns that involve unequally spaced beats or bars (for examples and discussion of these so-called additive metres see Rhythm, §1, 7–8). Conventional metres may also be used as a convenient way of notating complex, irregular rhythms. In these cases, performers may engage in metric counting, but listeners are not able to infer any pattern of beats, bars and so forth, in which case it is doubtful if any metre is truly present.

See also Notation. For bibliography see Rhythm.

JUSTIN LONDON