The phenomenon now known as Arena Rock was born at the California Jam and Deep Purple were at its epicenter. In many ways, the California Jam was the equivalent of the Woodstock festival to a burgeoning generation of hard rock and heavy metal fans. The Jam took place at the Ontario Motor Speedway in Ontario, California on a hot and sunny spring day on April 6, 74. The event attracted an enormous crowd of a quarter-million people and represented a baptism of fire in more ways than one for Purples new boys, frontman David Coverdale and bassist/vocalist Glenn Hughes, who in 73 had replaced Ian Gillan and Roger Glover, respectively, to usher in the bands so-called Mk III line-up.Deep Purple were literally on fire during that time: due to some behind the scenes feud with the promoter, Deep Purples performance was full of fire and fury no wonder their opening song was Burn. At the climax of the show, a still-furious Blackmore trashed several of his guitars and chucked his amplifiers off the edge of the stage. Blackmore also struck one of the cameras with his guitar. The chaos continued when a massive on-stage detonation created an out-of-control fireball pun most definitely intended. In the midst of all this mayhem there was also some awesome music being created. Purples set focused strongly on their then-current Burn album, the first by the Mk III line-up and only included a handful of songs from the previous Mk II era.Even in 2016, Glenn Hughes has very vivid memories of Deep Purples tempestuousCalifornia Jam performance: It was a moment in time for us all. It was a great statement of what rock was all about in that pre-MTV era. Its also a great testament to the Mk III line-up. Its big, its grandiose, its funky, its rock its Mk III in all its glory.