ï~~Proceedings of the International Computer Music Conference (ICMC 2009), Montreal, Canada
August 16-21, 2009
Musicians (1976). As in Drumming (1971), patterns are
gradually constructed by substituting notes for rests in a
pre-defined motif: only one or a few attacks of the motif
are played, then new attacks are added with each iteration
until the motif is completed. As in Octet (1979), NYC is in
12:8 meter and "exploits the ambiguity between whether
one hears measures of three groups of four eighth notes or
four groups of three eighth notes" [10c].
little by little (see Figure 1) and, once completed, they are
handed over to one of the pre-recorded tracks. The live
performer builds up 5 motifs, so at the end of this section,
a six-part counterpoint (Groove 2) is played by tracks 1-6.
D ] 3) E (K z)
[ (x)
12 ( 2)
I A kh LZ Au %.W
2.3.3. Structure
The 3 movements of NYC [fast-slow-fast] are played
straight through without a break. The change of tempo has
the simple ratio of 1:2 (quarter note= 184 in the fast
movements and 92 in the slow movement). As in many
other pieces, Reich doesn't restrict his music to a perfectly
defined tonality. By avoiding cadence and constructing
patterns, he constantly maintains the ambiguity between
modality and tonality. However, in this paper we will
focus more on the rhythmic aspect and patterns
construction than the harmonic and modal/tonal structures.
The score excerpts are written in Bb, so that Bb
clarinets are sounding a major second lower and Bb bass
clarinets are sounding a major ninth lower. Clarinet 1 to 10
are pre-recorded on tracks 1 to 10; clarinet 11 refers to the
live performer. Numbers (N) correspond to the markers on
the original score from Boosey & Hawkes (1985). We
define "Groove" as a rhythmic effect resulting from the
superposition of several motifs. Mix, M2x and M3x refer
to individual melodic motifs used in the 3 movements
respectively. RM3x refers to the rhythmic motifs appearing
in the last movement.
2.3.4. First movement -fast
Section 1 (Beginning - 5 measures after N07)
As in Music for 18 Musicians, the piece begins with a
pulse session we call Groove 1. Six Bb clarinets (live
performer + tracks 1-5) and 3 bass cl. (tracks 8-10) repeat
single eighth notes whose combinations constitute a
pulsing chord. Four different chords form a harmonic
evolution that is repeated twice. Each chord is constructed
from a perfect chord on which Reich adds fifths.
Thanks to a fade in / fade out technique and overlapping
between voices, the sound result is constantly flowing.
Each chord seems to come from far away, approach the
audience, and disappear again in order to let a new chord
emerge. This produces strange coloring, almost like
electronic sound. After traveling in Ghana, Reich became
aware that "acoustic instruments could be used to produce
music that was genuinely richer in sound than that
produced with electronic instruments" [10Ob].
Section 2 (5 measures after N07 - N36)
A motif is played by cl. 1. The live performer then plays
a new motif that creates resulting patterns in combination
with the pre-recorded music. Individual motifs are built up
Figure 1. New York Counterpoint, mvt. I- An example of
a melodic motif gradually built up by live clarinetist.
Beat-class sets (a rhythmic analog of pitch-class sets
denoting which beats are attacked in the motif) are related
according to the following time transposition. The 6 motifs
(Mla, Mlb, Mlc, Mld, Mle, Mlf) are identical
rhythmically but some of them are shifted by 5 or 8 beats
(see Figure 2): MIa=MId, MIb=tsMIa=MIe and
M1 c=t8M1 a=M1 f (equality refers only to the rhythmic
structure and tn refers to the time lag in number of beats,
i.e. eighth notes, between each motif). For more details
concerning accentual properties of the patterns and their
combination in NYC, see the excellent paper written by
Roeder in 2003 [11].
Resulting
melody
G
R
0
0
V
E
2
G
R
0
0
V
E
1
Figure 2. New York Counterpoint, mvt. I- Groove 1
(tracks 7-10) is a pulse chord. Groove 2 (tracks 2-6) is a
six-part counterpoint. Live performer plays a resulting
melody (each note is coming from Groove 2).
495
