There were two highly anticipated songs the crowd wanted to hear. Of course, Deep Purple played Smoke on the Water, their best known song from classic 1972 album Machine Head, and you couldn't help but grin with delight as guitarist Steve Morse - original Purple axeman Ritchie Blackmore has long since left the band - casually launched into those distinctive opening chords.
And you couldn't help but shout along as singer Ian Gillan, who, at 67, can still hit the high notes and let rip with his guttural growl, sang, "Smoke on the water ... and fire in the sky".
But earlier, there was an equally rousing, all-in crowd sing-a-long when American soft, and sometimes heavy rockers, Journey played their 1981 hit Don't Stop Believin' - the song made famous most recently when it got the Glee treatment. It's one of those guilty pleasure songs, but as my mate (a part-time Journey fan) also pointed out, in a bid to give it even more cred, it was the song that played during the final scene of the Sopranos finale.
Such is the power of Journey, and serenades like the beautiful Who's Crying Now and Open Arms (where the band's latest singer, Filipino import Arnel Pineda stretched out his soaring and velvety voice), that there were outbreaks of man love among a group of three lads who had been singing along to every song and breaking into air-guitar solos. But while it's anthemic tunes that Journey do best, they also showed a tougher side on the (almost) prog-metal of Wheel In the Sky and the punky Keep On Runnin' with wailing and flailing drummer Deen Castronovo taking on lead vocals.
Deep Purple were among the heaviest rock bands back in the 70s. And while not so fearsome these days, they don't take long to get their heavy metal gallop on with Hard Lovin' Man, and The Battle Rages On is the first real head-banger of the night with its grunty metal riffs off-set by its lyrical and vocal grandeur.
But courtesy of cool, calm and collected drummer Ian Paice, they can rein the songs back to a tight blues band jam, and even a hammering porch song like Lazy, before ratcheting the songs up to powerful and sprawling crescendos.
And the bombastic keyboard alchemy of Don Airey (playing parts written by founding member Jon Lord who died last year) ranged from spooky doomsday wurlitzer to a noisy wall of distortion that led into Perfect Strangers.
While the laborious drudgery of Wasted Sunsets dragged a little, they ripped through Machine Head's other hit, Space Truckin', before Smoke, and the highlight of the encore was Roger Glover's bass solo that went from surf guitar (on a bass), into rolling thunder, and then arse-shaking boogie woogie, before a storming Black Night from 1970 to end.
The thing about Deep Purple is that even after 45 years they still look like they're having fun up there - even when they still have to play Smoke On the Water for the millionth time.
What: Deep Purple and Journey
Where: Vector Arena