If you watch closely you will find that not only does the internal decoration of the house change (in ways not included in the plot) to become gradually darker as Tony is gradually undermined and seduced by Barrett but also the excellent (but very much of its time) soundtrack by Johnny Dankworth & (surely - or is my recollection wrong?) Cleo Laine - though the same LP is put on the turntable many times, the arrangement of the same theme is different. (I did not notice this at first but found it pointed out in a special issue of the Oxford University magazine Isis at the time the film was released that was entirely devoted to it.) The film has recently reappeared in England as a stage work: Play without Words, seen at the National Theatre, is (was, I guess, is more accurate) a superb piece of dance theatre in which the ambiguities of the characters' motivations, or the discrepancies between their thoughts and actions, are portrayed by having more than one dancer per character. Sometimes only one is seen, sometimes they move in unison, sometimes in separate ways. It is extremely effective.
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