Oblique organum
  • [For the benefit of those who've never heard either the word "organum" or the expression "oblique organum", the first refers to the singing of a melody in two voices, at the interval of a 5th, and the second refers to the practice of singing in organum, but breaking the parallel fifths to avoid either notes which are not in the mode or which would make 'forbidden intervals']

    Has anyone tried this morning's Communion Antiphon, Amen dico vobis using either fixed or oblique organum?
    Thanked by 1sdtalley3
  • sdtalley3sdtalley3
    Posts: 223
    Not this one, but we did do the Introit for the Midnight Mass at Christmas, "Dominus Dixit" utilizing parallel 5th organum.
    Thanked by 1ServiamScores
  • CHGiffenCHGiffen
    Posts: 4,744
    In addition to being sung at a perfect 5th, organum may also be sung a the interval of a perfect 4th, usually depending on the mode.
  • Richard MixRichard Mix
    Posts: 2,400
    Not to mention organum of the octave. At the Gospel we nearly always sing the final 3-fold Alleluia in fifths, octaves and twelfths.
  • MarkS
    Posts: 268
    In music history the term organum refers to a range of early polyphonic practices from the 9th to 12th centuries. In the earliest, simplest form, the two voices started on a unison and then split, one voice maintaining the starting pitch while the other ascended stepwise along the melody until (generally) the interval of a fourth was reached; there might then be a series of parallel fourths (generally not fifths) until the parts re-converged on a unison at the cadence. (See for instance the excellent article in The New Grove.)
  • CatherineS
    Posts: 652
    I'm only familiar with the kind MarkS describes, done on a psalm tone, in which the lines diverge mirror-like and then return to each other. It's very cool.
  • CHGiffenCHGiffen
    Posts: 4,744
    Diverging "mirror-like" is actually different. "Oblique" refers to one of the two voices staying on the starting pitch (same note) until a 5th (or 4th) is reached by the melody and then proceeding in parallel.

    Try singing "O come, o come, Emmanuel" by singing "O come, of come, Em-" on the starting pitch and then proceeding at a 5th below the melody from that point on.
  • So, here's my follow-up question:

    Given that on the syllable "-men" there is a half step (from la to te) and no comparable half-step a fifth lower, would one sing the fifth (and thus add a flat to the lower note) or stay on re (allowing a minor sixth)?
  • BruceL
    Posts: 1,066
    I believe the incipit, or at least the first few notes, would usually be rendered without the extra voice(s). So, no problem! :)
  • I read once that on a Mediteranean island the chant is sung in 'organum' at the major second during Lent.