The Deceitful Face of Hope and of Despair

‘The English title of my flute concerto - translated roughly as ‘ ... The Deceitful Face of Hope and Despair' - is taken from the poem “Ash-Wednesday” by T.S. Eliot. However, it was far from my intention to depict the emotional states mentioned in the title with musical means. I am much more interested in musical-acoustic facts. As we know, every interval produces two combination tones: a summation tone and a difference tone. For example, an interval sounding in the lowest register produces a difference tone, which we no longer perceive as a tone, but only as a pulsation. The smaller and the lower the initial interval, the slower the pulsation of its difference tone. And if the initial interval is shifted further and further into the depths, then we reach those areas where we can no longer perceive the real sound. All that remains is the pulse, which also gradually disappears ...’