Ligeti was active in the renewal of writing for certain instruments such as the organ (Volumina) or the harpsichord (Continuum).

The musical discourse is very homogeneous, based on the idea of continuity, of stasis, of a sound that slowly unfolds and transforms itself. Playing on the ambiguities of perception, the limit between the continuity and discontinuity of events. Organisation by masses and sound fields (density, dynamics, colour), over extended periods of time. Volumina was commissioned by Radio Bremen, dedicated to Hans Otte and Karl-Erik Wellin. It was composed in 1961-62 and revised in 1966. It is durations approximately 16 minutes. In the 1966 score Ligeti used graphic notation, supplemented by handwritten instructions. He created a legend to explain the symbols used to describe chromatic, diatonic and pentatonic clusters as well as clusters with moving contours or internal chromatic movements.

“The broad form of the piece must be conceived as a single large arc: there is no break in the play, nor any real break; [… ] The stationary sound spaces and their gradual and continuous change should be realized by the performer in such a way that the sound states and processes give the impression of great calm.” (György Ligeti, free translation)

Performing this piece requires a special technique of grouping, using forearms, fists and the flat of the hand. The term for this is clusters.