Musical 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 proposed mode as a general term but limited for melody types, which were based on the modal interpretation of ancient Greek octave species called tonos (τόνος) or harmonia (ἁρμονία), with "most of the area between ... being in the domain of mode" (Powers 2001, §I,3). This synthesis between tonus as a church tone and the older meaning associated with an octave species was done by medieval theorists for the Western monodic plainchant tradition (see Hucbald and Aurelian). It is generally assumed that Carolingian theorists imported monastic Octoechos propagated in the patriarchates of Jerusalem (Mar Saba) and Constantinople (Stoudios Monastery) which meant the eight echoi they used for the composition of hymns (e.g., Wellesz 1954, 41 ff.), though direct adaptations of Byzantine chants in the survived Gregorian repertoire are extremely rare.

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).

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