C. Chorale Bicinium
The bicinium is one of the more antiquated approaches to chorale settings. Reaching its height in the organ settings of Jan Pieterszoon Sweelinck (1562-1621) and Samuel Scheidt, it virtually disappears by the late seventeenth century. Dormant for over two hundred years, it began to find new life in the second quarter of the twentieth century in the hands of composers such as Hugo Distler (1908-42) whose interest in the early Baroque brought forth a revival of its forms and manner of developing materials.
The bicinium typically alternates each phrase of the chorale (in or close to its original form) between two soloistic voices. Original material of a quasi-improvisational character is composed against each phrase in the free voice. These passages usually consist of intricate and ornate filigree, often (but not necessarily) with some motivic connections. It is the very bare quality of this form that provides for its unique character, and along with it, special demands on the composer to maintain interest and drama within such an exposed texture. Implied harmonic progressions should, however, remain the basis for the contrapuntal extrapolations and thus guide the logic of the new material. Overall, what should be remembered most is that the bicinium is at its best an engaging interplay between two voices of absolutely equal significance and fluidity. Although there are no occurrences of voice crossings in our composition below, this is something that does not need to be avoided as bicinia are normally performed on two separate manuals.
We have chosen to begin with the first phrase of the cantus in the bass, cutting short the last note just a bit to allow for a brief change in texture. The interaction between sixteenth and thirty-second note rhythms displayed in this initial counterpoint will become the impulse for the remaining phrases. Note that the final beat of the treble line in bar 2 descends to meet its first cantus note in bar 3; this idea of a seamless segue is continued throughout the remaining three phrases.
In bar 4 we notice a brief chromatic ascent, recalling a similar passage in the Scheidt setting, in an otherwise freely devised line.
As we begin the third phrase, in bar 5, a three-step sequence is employed to allow for a moment of repose from the liberal flourishes that have typified the counterpoint thus far. This passage ultimately leads to the climax (about two-thirds through the piece) with a single high Bb quickly followed by a dramatic descent of parallel sixths that will bring us to the final phrase.
Since the first and last lines of Nun komm are identical, the free treble voice we composed in bars 1-2 can be converted into the free bass part in 7-8. This use of invertible counterpoint (wherein two or more contrapuntal voices are exchanged) brings closure to the piece by recapitulating opening material almost verbatim. A very brief codetta is added by extending the final note of the cantus and developing the last bass passage of bar 8 an octave lower.
mp3 download (two manual organ version)
