“This text offers the opportunity to play a homogeneous piece with a process.”
Note: The ‘warmth’ as used in the text can also be understood in a physical sense. (See: recording of INTENSITY with Karlheinz Stockhausen from 29 August 1969, Stockhausen-Edition CD No. 14)
’Sustain it as long as you can’: The aspect of ‘ability’ here has a double meaning, 1. until you feel that it is enough, i.e. it makes no (musical) sense to pursue this process any further, or 2. until a physical, instrumental limit has been reached, and it makes no (musical) sense to go beyond that limit.
Despite the division into two paragraphs, the piece is not meant to have two movements, but rather be one continuous process.
The performance instruction at the end does not allow a “contemplative conclusion” or a concluding quiet phase. When the (however defined) limit of ability, of continuation has been reached, then the piece has reached its conclusion.
Definition of ‘single sounds’: They should be separated from each other by rests or by maximum parameter-changes. The aspect of the individual should be clearly emphasised (in register, timbre and duration, inner activity). “It doesn’t say to play intervals or groups or play conglomerates of tones. The details must be especially emphasised – from the beginning to the end, by the way.”
For example, it possible to attain the ‘warmth’ described in the text by increasing the intensity of inner activity within a sound (“it is not only meant associatively”). This possibility is much more difficult for the live electronics player to realise (here: synthesizer).
Note on the time proportions: “The average duration of your results is too mediocre.” In order to allow intensity to develop, a tone can easily be developed over a duration of 4 minutes (at a total duration of 11 minutes in this case). This way, it is possible that a single player will only perform three tones altogether, but the decisive aspect is the intended increase in intensity (instrumental as well as mental): “I try to become so intense that I really start to sweat.”
The performance instruction ‘single sounds’ applies throughout the piece: “Internally lively figures are good, but please, only as a characteristic of single tones.”
Interaction between instrumentalists: “This is not really a piece about being considerate of each other. Each player concentrates on the single tones, makes sure he places them where there are no others, so that they can be clearly heard – and makes them as diverse as possible in all parameters.”
‘Single tones’: “As soon as I interrupt the tone by pauses, it is a series of tones. Play a homogeneous tone and then a pause and then play a different one, . . . please only play individual tones, but it must be a homogeneous body.”
The individual character of the tones is decisive. No repetitions of the same tone should be played. Repetition and internal activity should be carefully differentiated. (later: “The text is actually a restriction.” – no melodies and lines, only individual tones)
“One must really make every possible effort and play an individual tone so long that one grows into the intensity – by action.”
If one ends the intensity process of a tone with a (sufficiently long) pause, then one should begin the next process with a completely different musical entity in comparison with the previous one; otherwise it might seem to be a continuation of the previous one.
If a player who is not a professional singer uses his voice, then it should be transformed into “a range in which it sounds very artistic.” (Technical manipulation to wage off the danger of dilettantism)
The single tones, like individual, differentiated human beings, should have as many differences as possible in all parameters. To achieve the intensity of performance that produces glowing warmth, long tones should predominate.