Blood On Satan's Claw holds a special place in the hearts of British cult horror fans for a number of reasons. Released in 1971, this tale of Satanic possession in a 17th Century rural community at first appears to be another clunky yet charming piece of whimsical English terror, but soon — like the best horror films of that period — reveals itself to be a dark, perverse and deliciously nasty piece of work. Its sense of creeping sexual menace and demonic paranoia may owe much to its B-movie status, which adds a genuinely bizarre verité to some scenes, but its soundtrack, while reportedly made on an equally tight budget, is no shlocky rush-job. Instead, it's a highly effective orchestral score that works well as a listening experience even without the accompanying visual delights.
Composer Marc Wilkinson, at that time Director Of Music at London's National Theatre, reflects the film's diabolic concerns with a repeated descending chromatic scale that makes liberal use of the tritone, the so-called ‘devil's interval.'On paper, such an idea seems rather too obvious, but Wilkinson's compositional skills ensure that the motif is played with great variety throughout, from stately to mischievous, and used consistently enough for the listener eventually to shiver with recognition at its appearance. Set against shuddering strings, the swoop and glide of an occasional ondes Martenot — an early electronic instrument whose unearthly tones echo that of the Theremin — and the mysterious chimes of a cimbalom, Wilkinson's eldritch melodies are genuinely atmospheric, with a devilish logic of their own, while more lyrical, conventional passages reflect the spare beauty of the British countryside in which the film is set.