Programme Note WHIRLS´ WORLD (1970) for wind quintet. 'Whirl´s World' was composed in 1970 as one of a series of works which explored the so-called musical ´difference-phenomenon´. This term (which I coined in connection with a series of lectures in California that year) indicates a motivic duplicity in which two - often very simple - melodic ideas come ´out of phrase´ with each other giving rise to a course of constantly changing conditions. In Whirl´s World the difference phenomenon is heard from the beginning where a three-note motif and a four-note motif are set against each other. It all proceeds lake a lightning-fast series of chess moves; first notenumber 1 of the three-note motif is moved then note number 1 of the four-note motif thereafter note number 2 of the three-note motif - and so on. This fast opening flows into a slow section in which the differences now appear as ´fluctuations´ between very closely related tones (of which one is sung by the musician). There is only one movement built up as an organic growth from slow to furiously fast whirling and back again to slow which can be heard as ´slow-motion whirls´ as a water-world of ripples and bubbles. All this is framed by the introduction described above and a corresponding conclusion in which the movement is now descending ending in the resolute bass full-stop. Per Norgård