The painter's material

For GRAU Gisela Brinkmann has painted 72 pictures with grey acrylic colour on the insides of 35mm glass-slides. Each slide posses an individually mixed and painted hue of polychrome grey.

The colour concept

For the production of these 72 hues of polychrome grey a system of 24 different colours (not including white, black or grey) were available: the 24 "basic-colours".

A polychrome grey is created by mixing selected "basic-colours". Gisela Brinkmann has noted down the ingredients of each polychrome grey as a recipe, the recipes are translated into a numerical code, from the numerical code the commands for the computer controlled projection is calculated: the score.

The score was handed to the composer Frank Niehusmann to organize sounds ("sound-colours") from this numerical code: Frank Niehusmann does know neither the 24 "basic-colours" nor the 72 hues of polychrome grey behind the numbers of the score.

The score (part I)

The score consists of two parts: (1) a system for the creation of sounds and (2) a time structure and a plan of procedure for the projection with representation of the cross-fades. The system for the creation of sound-colours (1) contains the information, which colours were used for the mixing of a polychrome grey (aspect of quality) and how frequently a colour appears in the colour mix (aspect of quantity).

Analogous to that Frank Niehusmann has mixed complex "grey-sounds" from basic sounds:
The system of the time sequence calculates the duration of the observation of each colour slide from the recipe of each hue of polychrome grey which appears on the respective slide. Moreover it has been calculated from each colour recipe, how long each cross-fading from the preceding or into the subsequent slide will last.

The sequence of the slides and especially the beginning and the end of the series are designed in such a way, so that at the end it could directly commence again at the beginning, and thus an "eternal" loop could become possible.

The composer's material

The 24 "basic sounds" corresponding to the painter's 24 "basic-colours" in the composition were created from sine waves on a Yamaha TX-816 synthesizer according to the methods of frequency modulation, and then converted into a stereo signal.

The painter was free to select her "basic-colours", and the composer was free to select his "basic sounds" as well. The selection of these "basic sounds" was made in such a way, that a maximum range of different sound colours and tone pitches could be represented within these 24 "basic sounds".

The score (part II)

The 24 "basic sounds" were transferred from the synthesizer to a tripleDat harddisc-recording system and - according to the "system of sound creation" (see above) - mixed to 72 complex sound colours corresponding to the 72 hues of polychrome grey of the painter.

Painting and music within the time

Painting and music coincide in the simultaneousness of slide projection and concert. The pictures are recorded on slides, the music on CD. Three slide projecors and a CD player are synchronized via computer. The way and the extent of the performance are defined by "commercial standards":

Picture carrier: Glass slide frames, size: 24 x 36 mm = 1 picture.

Standard storing system for 24 slides = 24 pictures.

3 round-magazines = 3 standard storing systems = 3 x 24 = 72 slides = a total of 72 pictures.

Sound carrier: Audio-CD = 74 min.

Annotation: Mathematically the length of the composition that result from the numerical code of the sound-mixes amounts to 21 min. and 29 sec. Since the composition is designed as a potential eternal loop it is repeated three times until the full 74 min. capacity of an audio CD is filled out, than it will stop in the course of the fourth repetition after exactly 74 min.