Musical language
As Pietro Massa was able to show, an intensive exchange of ideas with the classical philologist Wolfgang Schadewaldt, the musicologist Thrasybulos Georgiades and with Wieland Wagner, the director who had originally been selected by the composer for the staging of the world premiere, accompanied the genesis of Orff's operas on subjects from Greek Antiquity. Orff made the decision, revolutionary for the time when the work was created, to set the original Greek text after extensive consultation with Wolfgang Schadewaldt, who advised the composer on detailed questions of Greek metrics. Since the quantitative metrics of Ancient Greek poetry are incompatible with the accent metrics of modern European languages as well as with the metrical structure of European art music, the composer chose the solution not to let the text, which had to be declaimed rhythmically by the singer's speaking voice during long passages of the opera, be decanted in a rhythm that corresponded to the ancient Greek meter of the original, but to add to the syllable order of the ancient Greek text the second layer of an autonomous musical rhythm. Since vast parts of the score require a rhythmic declamation of the Greek text in the speaking voice of the soloists, which is only occasionally interrupted by strong accents of the gigantic percussion, the score of Prometheus also marked a new stage in Orff's departure from traditional pitch structures in comparison with his previous operas on Greek dramas.
Concentrating on an ensemble of percussion instruments with a specific and indefinite pitch, originally certainly born out of the fascination that the orchestra's only still evolving group exercised on 20th-century composers, appeared to be a veritable patent solution for a composer for whom the creation of purely diastematic organizations had never been a central concern. The idea of a differentiated cooperation based on the division of labor, which has distinguished the orchestra of Western art music that has grown organically over the centuries, in the orchestra of Orff's operas on Greek Antiquity appears transposed onto instrument constellations that were previously unknown to European art music. In the score of Prometheus, the four pianos and the xylophones, which in the traditional orchestra were only given marginal tasks, take on the role that the string body had in the orchestration of Viennese classical music. On the other hand, the basic instruments of the traditional European symphony orchestra – such as flutes, oboes, trumpets and double basses – become entrusted in Orff's scores with functions that had been the realm of the rare percussion instruments in the 19th-century orchestra tradition. Their special timbres, which possess an almost exotic sound appeal, are only used for special, dramaturgically motivated tasks.
The inclusion of numerous non-European percussion instruments that had not previously been used in the orchestra of European art music cannot be interpreted as musical exoticism, especially since the composer hardly uses the new timbres unmixed. Rather, the gathering of instruments from all parts of the world in the orchestra of Orff's last works for the stage serves to substantiate the claim that the setting of the ancient Greek myth should reveal the all-encompassing nature of the Greek myth which appeals to mankind in its entirety.
In the history of 20th-century music, Orff's operas on subjects from Greek Antiquity appear as an extraordinarily original development of musical dramaturgy after 1949. In recent decades, and especially after the year 2000, Orff's late style has attracted an increasing interest from opera houses and from musicological research alike, not least because of the obvious relationship between Orff's musical language and the tendencies of minimalism.