This will appeal to a narrow group of people who are interested in experimental cinema. It can in no way be regarded as an "easy" introduction to Britten's great War Requiem oratorio. You need to know the oratorio itself and some background to the poet Wilfred Owen in order to make sense of the film. Much of the libretto comes from the Latin Requiem Mass and no text or subtitles are provided. Getting to know the oratorio itself is worthwhile homework, as it ranks as one of the major musical achievements of the 20th Century, with a universal and very moving impact. So if you don't already know the oratorio, get a CD of it first (one that contains the libretto with translations) or better still attend a live performance, and be prepared for an unforgettable experience.
The original Decca audio recording of the musical work is presented in its entirety without interruptions or additions, apart from a short prologue spoken by (and featuring) Sir Laurence Olivier (incidentally, his last performance, made shortly before his death). The visual material varies between illustration of, and reaction to, the musical work. At its best (e.g. the Hiroshima scene towards the end) it combines brilliantly with the music to overwhelming effect, but at other times can seem curiously at variance with the oratorio text. This is a film on which critical opinion is likely to be deeply divided.