Sound-mass technique
Layering of surfaces of sound, e.g. in Ligeti.
What it means
Sound-mass technique (German Klangflächentechnik) designates a compositional procedure in which not individual melodies or chords stand in the foreground but extended surfaces of sound. These arise by layering many voices at close intervals, often in dense tone clusters, which change slowly within the surface. The ear then no longer perceives individual lines but an overall colour whose density, extent, and motion change gradually.
Musical use
The procedure belongs to music since the middle of the twentieth century and shifts attention from pitch and rhythm to tone colour, density, and course. The individual voices can well be notated exactly and execute movements of their own; decisive is that they merge in the result. From the sum of small movements a large, slow change arises — a principle occasionally called micropolyphony. Formally, processes replace the traditional building blocks: instead of themes and developments there is thickening, thinning, wandering of the registers.
Performance practice
Play your part exactly, even if it is not individually audible in the overall sound; the effect arises from the sum of exact individual contributions. Keep volume and tone colour stable and avoid personal emphases, because they break up the surface. Count consistently, since orientation by ear is hardly possible in dense surfaces. Watch the notated transitions and when your part enters or exits. Check the effect in the room, because density and reverberation strongly influence each other.
Bear in mind that such scores are notated very exactly although the result sounds like a surface: the individual part is no arbitrary contribution but contributes to the density, and inaccuracies add up. Count consistently and keep your entries exact. Practise entries and transitions with a stopwatch if the score uses time indications in seconds. Watch microtonal markings, which often occur in such scores, and practise them with a tuner. For rehearsal work it is worthwhile to hear partial groups separately and only then bring them together.
Settle in rehearsal which voices enter and exit at which point, because the transitions otherwise seem unclean.