Here's a cross favoured by fans of hot-rods, rockabilly and the general rock'n'roll scene. 'Worldly' music such as theirs is affectionately known as the Devil's music, adding to the rebellious appeal of the music. Or noise, depending on taste. The pink-edged cross is a naive attempt to mock the highest authority.
This symbol is associated around the world with motorcycle gangs such as the Hells Angels and those who, for reasons best known to themselves, wish to imitate the Hells Angels. The Japanese bosozuko bike gangs have their own tribal identity (see Tasuki Cross) and the cross on the right bears the name of a popular Japanese bosozuko rock'n'roll group, the Kishidan.
Heavy metal music is supposed to provide a channel for the Devil through the use of tritones, a musical interval that spans three whole tones, like the diminished fifth or augmented fourth. Tritones can sound a bit spooky and doomy to the Western ear, and they were suppressed by the Church in the Middle Ages, labelling this musical phenomenon as the Diabolus in Musica (the Devil's Interval).
The esoteric school of Pythagoras taught that these can trigger a sensual state of mind - something the Church considered was a satanic temptation and consequently they made tritones illegal. This sounds ludicrous today, but we must remember that in the Middle Ages, their understanding of physiology was limited to drilling holes in people's heads (trepanation), far removed from today's neuroscience. Illness was considered the work of the devil and any sexual reaction within their bodies meant a supernatural power was taking hold of them. Why this should be the Devil and not God, remains a mystery.
Examples of tritones can be heard in Beethoven's Fidelio, the song 'Maria' in West Side Story, and the TV Simpsons' theme tune. You have been warned!