After the end of World War 2, Cerha focused on concertizing and teaching the then dominant neo-classicism (his Divertimentoof 1948 represents homage to Stravinsky). Later, he took as starting points the works of Anton Webern, and from 1956 serial techniques of the avantgarde, developing his own style with such pieces as Relazioni fragili, Espressioni fondamentali, Intersecazioni. With works such as Mouvements, Fasce and his Spiegel cycle (1960-61) he created his own language of sound free from traditional schemata. Despite apparent similarities with works written at the same time by Ligeti or Penderecki, it differs in so far as clearly recognizable processes of development play a major role, and in combination with non-linear processes major formal relationships are created, providing the work with a coherent system, a sort of cosmos. In the project “Welttheater”, which has not as yet been staged, the patterns of behaviour of humans in the mass are mirrored, so to speak, at a distance in space and time, by mass structures in the musical processes.
In the stage piece Netzwerk, which derived from the basis of the deliberately heterogeneous material of Exercises (1962-67), the perspectives switch between mass reactions and individual areas surveyed as if under a microscope. Regressive stylistic and structural elements break into a purist world of sound, and create complex relationships of disturbance and order in an organism corresponding to ‘the world as a network’. After a series of instrumental works in which he extended his material by referring directly to historical idioms (Curriculum, Sinfonie), the opera Baalseamlessly knits together all the previous structural forms. The individual now appears provocatively as the centre of interest, but the range reaches from “Spiegel“-like fields of sound, standing for the most basic principles, to clearly articulated melodic and harmonic forms in which the differentiated involvement of the individual is reflected.
In the opera Der Rattenfänger(The Pied Piper) (1984-86) it is above all polyrhythmic patterns with the significance of leitmotifs which provide integration but at the same time tension. Cerha took a fresh look at various forms of folklore, already evident in his early works, in such minor works as the Keintaten(after Ernst Kein) and Chansons(settings of texts of the Vienna Group), stylising and alienating the Viennese idiom. On the other hand, his string quartets, some of which use microtones, show the influence of non-European music, with a tendency to polyrhythmic and metrical forms also to be found in other works such as the Langegger Nachtmusik III and Quellen. His latest works again confirm that Cerha’s interest – dating from 1962 – is still to deal with a multiplicity of experience in complex musical organisms.