As Johnston recalls, when asked to compose The Undertaker's theme, he was given very little information besides him being a "very large, dead man." The name was enough to go on, as he sought inspiration elsewhere. Largely based on the Marche Funèbre movement from Chopin's second sonata, Johnston composed a haunting death march for solo piano very much in the style of the Polish Romantic.
But something about it wouldn't quite work for a near-seven foot tall mortician, so he imagined if 'Taker had been interred at St. Paul's Cathedral. What'd play at his funeral? The same tune, but on a humongous pipe organ.
Satisfyingly, the legendary theme was played on such an instrument for real when WWF visited London's Royal Albert Hall in 1991.