"There shouldn't, theoretically, be anything scary about a musical interval. Just as turning round three times with your eyes closed while reciting the Hail Mary probably won't make the devil appear before you, despite generations of schoolchildren believing otherwise, so playing the note of C followed by F sharp shouldn't encapsulate the essence of evil - but somehow it does. The movement from the first tone in a scale to the fifth, known as the perfect fifth, was the first accepted harmony of the Gregorian chant after the use of the octave. It was discovered in the 11th century that moving down a semitone to the diminished fifth created dissonance, and a nasty feeling of foreboding and dread. The church of medieval Europe quickly banned it, reputedly relying on torturous methods to ensure that the ban was upheld...The Devil's Interval does, however, have a foreboding history. The 18th-century violinist Giuseppe Tartini claimed that he composed his Devil's Trill Sonata after Satan himself gave him instructions on how to do it, which might help explain why this piece of music is so incredibly difficult to play. In Wagner's Götterdämmerung, the diminished fifth illustrates a scene of pagan excess; Camille Saint-Saëns used it to tell the story of skeletons coming alive at Halloween in his Danse Macabre. Jimi Hendrix nailed it in the intro to Purple Haze to bring home the message that hallucinogenic drugs may be exciting but they're scary, too..."
Will Hodgkinson on the diabolical Tritone.
