The composer (from the CD booklet):
"Theory of the oscillating universe: every 80 000 000 000 years the universe explodes, unfolds, and draws together again. The word YLEM is used by some people to designate the periodic explosion, by others to designate the essential material. […]
"At the beginning, 10 of the 19 players stand on the stage around the piano; after a sound explosion they walk playing into the hall and take up position to the left and right of the audience (the remaining 9 players stay on stage). Towards the end they go back onto the stage, stand around the piano, and after a second explosion, all 19 players walk off the stage and out of the building, while continuing to play (the 9 players who were playing on stage have small portable instruments)."
The explosion of sound at the beginning involves many or all instruments at once. Then single instruments play, but with their sounds densely overlapping each other. The sound events become more and more drawn-out and form a less dense texture, up to the point where, after a few minutes, the overlapping of sounds makes place for individual sounds, or for louder events singled out against a background of more quiet ones. At that point, the music seems to be born from silence, a silence from which the instruments emerge with their gestures. This silence finally becomes very concentrated and tense; the musical gestures become very isolated against that background.
From there, the musical process is gradually reversed. The sound events follow each other more closely again, and the music becomes more and more dense and loud, until finally a second sound explosion follows, quite similar to the one at the beginning of the work. Again a musical process analogous to the one after the first sound explosion follows, and the players walk off stage and out of the building (see above), playing all the time until they are not audible anymore.
The sounds and gestures in this work are characterized by their concentration on invariant pitches. Mostly the instruments play short punctuated notes, sustained single tones or chords, rhythmically accentuated note repeats, or gestures fluctuating around single pitches or chords.
The brass instruments rarely play really soft, the woodwinds mostly do not play really loud. The dynamic behaviour of these two for this work very important instrument groups gives the impression that the music plays on different dynamic plateaus which do not interact with each other, rather, which move parallel to each other.
The CD contains two recordings of the work (duration about 26 min. each), made in close succession (in total three recordings were made in a time span of just 3 hours). At first I was disappointed that the CD contains two recordings which initially sound so similar, but then I discovered that it makes perfect sense because it is very instructive about the way the music is composed and played:
The score is a text score (!) and does not contain notation; within certain confines (the composer only defines the general outline of musical gestures) the musicians are free to play what comes to their mind while listening to each other. The comparison and enjoyment of both recordings with respect to this makes for an involving experience.
"YLEM is a music which best succeeds when the players establish telepathic communication with one another (they play with eyes closed) and with a "conductor" who listens with extreme concentration from the middle of the hall, but is not outwardly active."
The fascination of the music lies in the realization of the compositional concept, which seeks to portray the oscillation of the universe – with the relaxation of dynamics and of density from the beginning towards the middle, and then the reversal of that process, followed by another period of streaming out from the point of highest density which eventually leads to the end of the work.
Also, there is the fascination of the free musical interaction of the players with each other. This interaction gives the whole composition an intensely improvisational feel in the sense that the music is really just created while the players continuously respond to each other's musical gestures – but according to the masterplan outlined by the composer.
The CD is available from Stockhausen-Verlag (CD 21). The recording captures two splendid performances by the London Sinfonietta in 1973; the recording, mixed down onto CD by Stockhausen himself, is in quality comparable to very good recent recordings (with the exception of marginal tape hiss). I had forgotten that my stereo could reproduce the pithy tone of a trombone this convincingly until the CD graced my player.
© Albrecht Moritz 2000, text edited 2005
Ylem (Stockhausen) - Wikipedia
Stockhausen: Sounds in Space: YLEM