OPCI

"OPCI” for Piano

My piece “OPCI” is built around the idea of ordered pitch-class intervals (OPCIs); each of the five movements is entirely composed based on specifically chosen sets of these intervals. Elements of symmetry and imitation also permeate throughout my piece. 

I. The sets of OPCIs guide the specific phrasing of this first movement. Each phrase begins with a new set of OPCIs, and throughout the phrase, the set is completed and then developed through techniques like retrograde and inversion. The sets appear melodically, but the intervals also appear in chords and harmony between the hands. This movement follows a binary form.

II. This movement follows a ternary form, with each of the sections beginning with a single chord. A set of OPCIs is derived from the chord from bottom to top; for instance, at the beginning of the movement, the set is [+2, +5, +7, +1]. Throughout each section, the right hand repeats the first interval both in an ascending and descending manner, and then the left hand eventually joins by playing the first interval while the right hand moves on to the second. To maintain symmetry in the movement, the hands begin by playing the A-section intervals backward, so the right hand starts by playing the +1 and then moves on to the +7 when the left hand comes in on the +1. Once both hands complete all the intervals in the set, the B-section begins and the process repeats.

III. The energetic third movement deals especially with contour and rhythm. To emphasize that this is the middle of the piece, I composed this movement to be particularly symmetrical in form and structure. This third movement follows a ternary form, and within each section is embedded another ternary form. Also, the set of intervals in the A-section is dominated by tritones, once again emphasizing the symmetry of the movement. The chords of the B-section are built from some of the OPCIs taken from the middle of the A-section, and the B-section retrogrades onto itself in terms of the order of OPCIs used.

IV. The fourth movement is particularly imitative. This movement revolves entirely around the set [+1, +4, +9, -6, -5, +2, +4, +9, -1, -4, -2, +9]. The left hand starts by playing the set, then plays it inverted, retrograded, and then retrograde-inverted. Meanwhile, the right hand comes in and plays the set and then the same order of variations. Then, the third voice comes in and plays the same line, after which the fourth, fifth, and final voices enter successively, playing the set of OPCIs, then the inversion, retrograde, and retrograde-inversion. The movement ends when the last voice finishes this progression.

V. Arguably the most neoclassical of the movements, this movement follows a rondo form as in standard classical fashion. The three A-sections are united in that they are built around the same set of OPCIs, although the second A-section features the set retrograded. The B- and C-sections follow their own sets of OPCIs by introducing them and then developing them by repeating in retrograde and inversion using various rhythms. This movement concludes with five loud chords, each of which is built from the most prominent set of OPCIs of each movement to tie the whole piece together.