Mauricio Kagel, "Acustica" (Side Four)

The work consists of two -- almost separate -- plains; one constitutes the playback of a 4-track tape recorder with a fixed sequence, whereas the second derives from the playing of 2 to 5 musicians which can be varied from performance to performance in the construction of acoustic material and in the manner of interreaction. I have deliberately avoided combining both plains as I have always had the impression-also in my works which display similar problems-that the attempt to weld together electronic and instrumental music is more wishful thinking on the part of the listener than acoustical reality. (On the other hand, this blending is immediately attainable if the total sound comes from the loudspeaker).

The four-track tape was produced in Winter of 1969 in the electronic music studio of West German Radio, Cologne (WDR). The recording consists of purely electro-acoustically produced material as well as recordings of instrumental and vocal sounds which were not manipulated. (Apart from the instruments, the voices of Alfred Feussner and William Pearson are to be heard).

The point of departure for this tape-composition was to compound as homogeneously as possible, two categories of sounds, dissimilar in the nature of their production (a combination which seemed to me over-simplified when produced by means of a metamorphosis of the concrete recordings by filtering, ring modulation, alteration of the tape playback ). It should rather be achieved by similar treatment of instruments and electronic sound-production.

The similarity between the procedure in the composition of the electronic material and the way in which I set instruments and their playing-function, made a mechanical transformation - mechanical since electrical, but worked by hand-of the recording unnecessary.

The instrumental part of the work was written on approx. 200 filing-cards, in the top right-hand corner of which the relevant main-instrument is indicated by a symbol. Neither the order of the cards nor the manner of ensemble are specified-every action is, however, exactly predetermined. The performers always decide the point of their entries; this freedom demands, however, a perfect mastery of text and context. Thus the performers achieve more than a mere reproduction of their parts, as they incorporate influences from another in their playing as if they were audience of themselves.

ACUSTICA, one of my most extensive works of recent years, is written in memory of Alfred Feussner, my early-departed friend.