Music Modes

In the theory of Western music, mode (from Latin modus, "measure, standard, manner, way, size, limit of quantity, method") (Powers 2001, Introduction; OED) generally refers to a type of scale, coupled with a set of characteristic melodic behaviours. This use, still the most common in recent years, reflects a tradition dating to the Middle Ages, itself inspired by the theory of ancient Greek music.

Regarding the concept of mode as applied to pitch relationships generally, Harold S. Powers describes a continuum between abstract scale and specific tune, with "most of the area between ... being in the domain of mode" (Powers 2001, §I,3). In this sense the concept has been extrapolated (long before the Power's article) not only to Western cantus planus monodic tradition but to Byzantine chant (e.g. Wellesz 1954, 41 ff.) and to Russian Znamenny chant (Kholopov 2003, 192) as well. Since the end of the eighteenth century, the term "mode" has also applied to pitch structures in non-European musical cultures, sometimes with doubtful compatibility (Powers 2001, §V,1). The concept is also heavily used in regard to the Western polyphony before advent of the so called common-practice music as for example "modale Mehrstimmigkeit" by Carl Dahlhaus (Dalhaus 1968, 174 et passim) or "Tonarten" of the 16th and 17th centuries found by Bernhard Meier (Meier 1974;Meier 1992).

The word encompasses several additional meanings, however. Authors from the ninth century until the early eighteenth century (e.g. Guido of Arezzo) sometimes employed the Latin modus for interval. In the theory of late-medieval mensural polyphony (e.g. Franco of Cologne), modus is a rhythmic relationship between long and short values or a pattern made from them (Powers 2001, Introduction); in mensural music most often theorists applied it to division of longa into 3 or 2 breves.

A "scale" is an ordered series of pitches that, with the key or tonic (first tone) as a reference point, defines that scale's intervals, or steps. The concept of "mode" in Western music theory has three successive stages: in Gregorian chant theory, in Renaissance polyphonic theory, and in tonal harmonic music of the common practice period. In all three contexts, "mode" incorporates the idea of the diatonic scale, but differs from it by also involving an element of melody type. This concerns particular repertories of short musical figures or groups of tones within a certain scale so that, depending on the point of view, mode takes on the meaning of either a "particularized scale" or a "generalized tune". Modern musicological practice has extended the concept of mode to earlier musical systems, such as those of Ancient Greek music, Jewish cantillation, and the Byzantine system of octoechos, as well as to other non-Western musics (Powers 2001, §I, 3; Winnington-Ingram 1936, 2–3).

By the early 19th century, the word "mode" had taken on an additional meaning, in reference to the difference between major and minor keys, specified as "major mode" and "minor mode". At the same time, composers were beginning to conceive of "modality" as something outside of the major/minor system that could be used to evoke religious feelings or to suggest folk-music idioms (Porter 2001).

Early Greek treatises on music do not use the term "mode" (which comes from Latin), but do describe three interrelated concepts that are related to the later, medieval idea of "mode": (1) scales (or "systems"), (2) tonos—pl. tonoi—(the more usual term used in medieval theory for what later came to be called "mode"), and (3) harmonia (harmony)—pl. harmoniai—this third term subsuming the corresponding tonoi but not necessarily the converse.