Who completed the orchestration of Alban Berg's unfinished opera Lulu?

Friedrich Cerha completed the orchestration of Alban Berg's unfinished opera Lulu.

Berg died in 1935 while working on Lulu, leaving much of the third act in short score rather than a fully orchestrated form. The first two acts were staged in Zurich in 1937, but the opera was not performed in its completed three-act form for decades.

Austrian composer and conductor Friedrich Cerha prepared the missing orchestration. His work made it possible for the complete version to receive its premiere at the Paris Opéra in 1979, conducted by Pierre Boulez and directed by Patrice Chéreau.

The completion is important because Lulu was already recognized as a major twentieth-century opera despite its unfinished state. Cerha did not create a new opera from scratch; he orchestrated Berg's existing musical material for the final act. Performances may still use the shorter two-act version, but the three-act edition is the completed form associated with Cerha.