Spinal Tap promoted the loudness of rock bands.. When they turned the knobs to 11 !!!  Many bands have claimed to be the loudest, measuring volume in various ways including with decibel  meters at concerts by engineering analysis. The  Guinness World Records no longer celebrates “The Loudest Band in the World” for fear of promoting hearing loss. In 1972 Deep Purple were the recognized leader at 118dB.. It was so loud that 3 people fell unconscious! Their record has, of course, been broken many times since. In 1975, Motörhead singer Lemmy famously joked that the band “will be so loud that if we move in next door to you, your lawn will die”. He said this at a time when bands were competing to break into the Guinness Book Of World Records as the loudest certified group – and, no question, Motörhead have always been among the loudest bands in the world.

According to the survey, the “standard” rock band performs at 110 decibels, while AC/DC, Led Zeppelin and Motorhead all crank it up to a whopping 130 decibels– the same sonic power as an air raid siren.  The Who set a world record that stood for eight years at 126dB’s. Townshend and Daltrey for years of being one of the loudest bands in the world left them with severe hearing problems. Daltrey, who admits he is now “very deaf”, said, “If only we had known when we were young.” Townshend later helped established the charity HEAR (Hearing Education And Awareness For Rockers).

Deep Purple–who after a lot of early creative experimentation and moments of serendipitous genius finally settled upon a sound that combined elements of prog rock, classical and the grinding blues-based hard rock that would become known as heavy metal–had their moments, and lots of them are to be found on their sixth and most commercially successful LP, 1972’s Machine Head. From its very metallic (the title’s stamped in steel!) cover to its far-out boogie numbers Machine Head is one wild ride, what with Ian Gillian’s shriek, Ritchie Blackmore’s blazing guitar, Jon Lord’s teeth chattering organ, and the positively intimidating drumming of Sir Ian Paice, who has yet to be knighted but certainly ought to be lest he become angry and start throwing punches. Its estimated that “Purple” sold over 150 million records!
“Space Truckin”, taken from the almighty Machine Head, is Deep Purple’s greatest achievement.  The organ driven track opens with one of the greatest organ riffs ever (one of the greatest riffs period), and Gillan’s vocals are just amazing.  No one alive can do the screams in the middle and at the end, not even Gillan himself can do it anymore.