Hypolydian.

The common name for the sixth of the eight church modes, the plagal mode on F. In the Middle Ages and Renaissance the Hypolydian mode was described in two ways: first, as the diatonic octave species from c to c', divided at the Final f and composed of a third species of 4th (tone–tone–semitone) plus a third species of 5th (tone–tone–tone–semitone), thus c–d–e–f + f–g–a–b–c'; and as a mode whose final was f and whose Ambitus was c–d'. In addition to the final, the note a – the tenor of the corresponding 6th psalm tone – was regarded as having an important melodic function in the 6th church mode.

The Hypolydian mode, however, even more than its corresponding authentic mode, the Lydian, was characterized by the prevalence of b, rather than b, at the fourth degree above the final. Glarean, in the Dodecachordon (1547), wrote that contemporary ‘musicians change the third species of 5th fa fa [f–g–a–b–c'] into the fourth species of 5th ut ut [tone–tone–semitone–tone, thus f–g–a–b–c'] … in this way it falls into the Hypoionian … which has been so injurious to this Hypolydian mode that it has almost been obliterated and destroyed’ (see Hypoionian). Actually Glarean was here a prisoner of his system. Historically, modal theory gave the predominance to b as early as Hucbald: ‘While examples of the tetrachord of the synemmenon [i.e. a–b–c'–d'] are often encountered in all the modes, or tones, they can be seen especially in the authentic and plagal tritus [i.e. the Lydian and Hypolydian modes]’ (De harmonica institutione, ed. C.V. Palisca and trans. W. Babb, New Haven, CT, 1978, 31).

For the early history of Greek-derived modal names see Dorian. See also Mode.

HAROLD S. POWERS