In Chroma 1, two pitch structures are audible simultaneously. One structure is presented on a loudspeaker in front of the audience, the other on the loudspeakers surrounding it. Both structures are based on a twelve-tone row with perfect- and augmented-fourth intervals. The two pitch structures complement each other in such a way that at various moments in the piece (articulated by a low-pitched sound) all chromatic tones within a range of two octaves have been used. The pitch structure of the piece was completely defined beforehand; all other parameters such as durations, timbres, dynamics and so on were freely interpreted during the actual production of the piece with one goal only: to make the pitch structures audible as clear as possible.
On the front speaker there are instrumental and vocal sounds, which underwent transformations in the frequency domain. The sounds on the surrounding speakers are exclusively derived from vocal material. A large number of transformations of this material were produced for the entire twelve-minute structure. Structures of the transformations on the surrounding speakers could be worked out differently, resulting in form variants based on the same pitch series. Chroma 2 was produced with this idea in mind: to produce a variant of the piece by systematically permutating the form of the surrounding structure while leaving the pitch series in tact. Eventually, the pitch structure on the centre speaker was deleted from Chroma 2 completely, being there only in the mind of those who listened to Chroma 1 first.
Chroma 1 was commissioned by the Fonds voor de Scheppende Toonkunst and premiered during the festival Inventionen 2006 at Villa Elisabeth in Berlin.
sketch for Chroma 1 
sketch for Chroma 2
year: 2006
duration: 11:55 / 11:55
tracks: 7
Chroma 1 is available on the 9 Trajectories CD-box (INA-GRM G6050/59).