Hailed by Stanley Kubrick as "Absolutely, one of the great films", Lindsay Anderson's stylish, surrealistic, uncompromising and confrontational film IF... encapsulated the revolutionary atmosphere of the sixties; and four decades on has lost none of it's power to astonish and provoke.  Malcolm McDowell (of whom IF... made a star), suggested the bewitching, other-worldly music of 'Sanctus' from the "Missa Luba", a version of the Latin Mass based on traditional Congolese songs, which establishes the film's very particular atmosphere.  IF... captured the public's imagination beyond anyones expectation and the memorable 'Sanctus' subsequently became a chart hit ("I couldn1t believe it" recalled McDowell).  Les Troubadours du Roi Baudouin, a choir, with percussion section, consisting of about 45 boys from 9 to 14 years old, and 15 teachers were formed by Father Haazen. The "Missa Luba" is pure Congolese. It is completely void of any modern, western musical influences. None of it is written. Certain rhythms, harmonies and embellishments are spontaneous improvisations.