“His name is Stevie Vai/And he’s a crazy guy” So run the opening lines of Frank Zappa’s Stevie’s Spanking, which Vai unexpectedly revives tonight, accompanied by a vintage video of his younger self playing the song on stage during that six-year tenure as Uncle Frank’s ‘stunt guitarist’. Alas, the rest of the lyrics are muted as Vai opts for an instrumental version. This means younger members of the audience who are unfamiliar with the Zappa oeuvre are denied the lascivious alleged details of his night with a accommodatingly strict “large and soft” lady who “gave him a wanking/after the spanking” and then proceeded to do unmentionable things with a hairbrush and banana. But hey, the guy’s just turned 56. Let him have his dignity.

Still, metal’s greatest vegetarian beekeeper is incontestably a crazy guy. Tonight he’s in nostalgic mood, reminiscing about the “outrageous clothes and crazy music” – or possibly the other way round – that he enjoyed with the likes of David Lee Roth in the ’80s. More specifically, it’s all about his biggest solo commercial success: 1990’s Passion and Warfare album. In retrospect, it seems bizarre that such a dense, complex and challenging instrumental recording should have sold more than a million copies and gone top 10 in the UK and top 20 in the US. During a break in proceedings, he confesses that he originally envisaged the project as a career-ending folly and didn’t even bother to tour the album when it was released.

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The show opens with a brief clip from Walter Hill’s Crossroads, with Vai cast, appropriately enough, as Beelzebub’s duelling guitar player. This leads into the heavy grooves of Bad Horsie, during which he makes his grand entrance clad in a Ghost-style hood with laser shades and illuminated guitar. That’s about it for the dressing-up box as he proceeds to heed the old Zappa maxim “shut up and play yer guitar” with an epic show that sees delirious outbreaks of air guitar, air drumming and even air bass playing among the packed audience, some 50% of whom seem to be fellow musos with jaws on the floor. It’s noticeable that while Vai’s old chum and sparring partner Joe Satriani plays live with some of the world’s greatest sidemen (generally moonlighting members of The Aristocrats), Vai’s band actually feels like, well, a band. The exceptional rhythm section of bassist Philip Bynoe and drummer Jeremy Colson are positively funky when occasion demands, while guitarist Dave Weiner succeeds admirably in the unenviable task of keeping up with his employer.

Passion and Warfare played in its entirety for the first time is the treat we’ve all been anticipating, though in truth this was not an album that was sequenced with live performance in mind – ending as it does with the rather odd studio experiment Love Secrets, for which Vai offers an upfront apology. Nonetheless, there’s no shortage of diverse guitary goodness within what we used to refer to as its grooves. Liberty is a suitably fiery opener, accompanied here by old footage of big-haired Vai playing it on stage with even-bigger-haired Brian May in a Seville enormodome. Satriani pops up on screen in pre-recorded form for an interactive chat that I’m guessing was inspired by Vai’s role as the narrator in Devin Townsend’s Retinal Circus project, prior to a guitar battle during Answers.

While a couple of these tracks are staples in Vai’s show to this day, others have been overlooked. “I’ve been waiting to play that,” he remarks after a blistering The Riddle. The lovely Ballerina 12/24 marks a change of pace and style, being a brief, mostly solo piece reminiscent in part of a Steve Howe showcase. Then it’s time for the big epic centrepiece, For the Love of God, which gets a suitably rapturous reception. Dream Theater’s John Petrucci appears on screen to join in with the album’s other enduring crowd favourite, The Audience is Listening. And it’s a joy to be re-acquainted with Greasy Kid’s Stuff and Alien Water Kiss. The only slight quibble is that he might perhaps have considered re-sequencing Passion and Warfare to climax on a high note.

But that’s probably why this show is bookended by additional material. After Stevie’s Spanking, it’s time for the traditional Build a Song segment, during which audience members are invited on stage to ‘sing’ rhythms and guitar melodies that are transformed into songs on the spot. “Don’t worry,” grins Vai, “Philip has such perfect pitch that he can even play in the key you’re thinking.” There are, of course, sensible limits: “No jazz – please!”

What he reckons without is a feisty lady named Denise, who immediately asks for an autograph on her own painting of the semi-naked guitarist and makes Bristol proud by veering off script. Asked to describe every woman’s fantasy, she’s fed the answer “to play guitar” but actually goes with “to sit on Steve Vai’s amp while he plays guitar and ride it like a Bad Horsie” Which is, of course, a much better response, even if it leaves him uncharacteristically speechless for a few seconds.

After more than two hours of sublime guitar heroics, Vai and his band don’t bother to leave the stage for the encore, launching instead into the sublime Taurus Bulba that concludes his grand Fire Garden Suite. Any chance of bringing Devin back for a Sex & Religion anniversary tour next time, Steve?

All photos by Mike Evans

Read more: Metal & Prog picks for June 2016