' could also occur ‘by
licence’). In addition to the final, the note a – the tenor of the
corresponding first psalm tone – was regarded as an important melodic function
in the first church mode.The common name for the first of the eight church modes, the authentic mode on D. Originally ‘Dorian’ was an ancient Greek tribal name that was used to designate one of the harmoniai, as mentioned in Plato's Republic or Aristotle's Politics, along with the names Phrygian, Lydian, Mixolydian and some others. The 2nd-century Hellenistic theorist Ptolemy of Alexandria used these terms, along with Hypodorian, Hypophrygian and Hypolydian, to designate the seven tonoi, or transposition keys. Four centuries later Boethius, basing his discussion on Ptolemy, described these seven names as toni, tropi, vel modi (‘tones, tropes or modes’) in the fourth book of his De institutione musica, still with the meaning of transposition keys. In the late 9th-century Carolingian treatise Alia musica, an eighth name, Hypermixolydian, taken from another part of the fourth book of Boethius's treatise, was added; this term was replaced by Hypomixolydian in the Nova expositio, a commentary on the Alia musica. This set of eight terms, beginning with Dorian and ending with Hypomixolydian, was given a new sense in the Nova expositio: it designated a set of eight diatonic species of the octave, each conceived as the juxtaposition of a 5th and a 4th, which were said to be the tonal embodiments of the eight modes of Gregorian chant.
In
the Middle Ages and Renaissance the Dorian mode was described in two ways: as
the diatonic octave species from d to d', divided at a and
composed of a first species of 5th (tone–semitone–tone–tone) plus a first
species of 4th (tone–semitone–tone), thus d–e–f–g–a + a–b–c'–d';
and as a mode whose Final was d and whose Ambitus was c–d', with upward
extension ‘by licence’ as far as e' or f' (the note b' could also occur ‘by
licence’). In addition to the final, the note a – the tenor of the
corresponding first psalm tone – was regarded as an important melodic function
in the first church mode.
‘Dorian mode’ is often used to refer to the general tonal organization of Renaissance and Baroque polyphonic compositions whose chief scale degree is D, whose parts range more or less within the Dorian or the Hypodorian ambitus and whose principal cadential degrees are D, A and F in the first rank and C, G and E in the second rank. Compositions of this kind, though their most important harmony is what is now called the D minor triad, cannot really be said to be in the harmonic tonality, or key, of D minor. This polyphonic application of the Dorian mode is often found transposed up a 4th to G, and works having the properties of the polyphonic Dorian mode but set in the cantus mollis (i.e. with a one-flat signature), and having G as their chief scale degree, are often said to be ‘in G Dorian’. As late as the 18th century, works in the tonal minor mode were notated as if in the polyphonic Dorian mode, with one fewer flat in the key signature and the flattened sixth degree treated as an accidental (e.g. Bach's solo Violin Sonata in G minor bwv1001).
‘Dorian mode’ is often used to describe European folksongs, and even non-Western melodies, in which the relationship of the most prominent scale degree (the final or apparent tonic) to the scale type seems similar to that in the Dorian church mode.
See also Mode.
HAROLD S. POWERS