Fluorescences for orchestra
Penderecki used this commission – his second from Donaueschingen Festival – as an opportunity to present a kind of encyclopaedia of sonoristic techniques and to take the world of musical sound far beyond aesthetic barriers. It was probably not a coincidence that the composer chose a title related once again, as with Anaklasis, to an optical phenomenon. This time the title refers to an emission of light by an atom that has absorbed radiation, having a lower energy than the absorbed radiation.
The form of this composition does not follow traditional patterns, but its cohesive and logical organisation, based on both sounds of definite pitch and on a wealth of non-musical cracks, clicks, noises, whistles and taps, allows the audience to “grasp” the whole as a succession of contrasted “sound shapes”. In the middle section, which researchers have named an “invention on one sound”, the composer surveys of various articulations of the note C. Staccatos and vibratos lead to a culmination that falls on a section characterised by maximum sound volume and intensity, produced by nearly all the orchestra’s instruments. Later the tension drops: the highest possible brass and percussion sounds merge into a cluster produced by the strings, pulsating against the background of a siren. Eventually we hear only double-basses, and the musicians gradually twist the tuning pegs to loosen the strings, so as to reach the lowest registers possible.