Requiem (Ligeti)

The work lasts for just under half an hour, and is in four movements: "Introitus", a gradual unbroken plane of sound; "Kyrie", a complex polyphonic movement reaching a fortissimo climax; "Dies Irae", which uses vocal and orchestral extremes in theatrical gestures; and the closing "Lacrimosa", for soloists and orchestra only, which returns to the subdued atmosphere of the opening.

Ligeti spent nine months working on the six-minute "Kyrie" section alone, which featured the most complex polyphony he had ever attempted, featuring twenty vocal lines, although as Harald Kaufmann notes, "it refers back... to the classical vocal polyphony of the old masters".

"[2] He scored the work for large choral forces, featuring two mixed choirs and soprano and mezzo-soprano soloists.

The work was first performed on 14 March 1965 in Stockholm, with the soloists Liliana Poli, Barbro Ericson and the Choir and Orchestra of Swedish Radio under Michael Gielen.

Ligeti's Requiem achieved almost instant fame (for a modern classical work) due to its use by Stanley Kubrick in his 1968 film 2001: A Space Odyssey, although the soundtrack only uses the portion from the beginning to the climax of the "Kyrie" section.