Mac DeMarco @ Victoria Warehouse, Manchester, 30 Oct

Mac DeMarco continues to make a mockery of the slacker label that’s so often applied to his music.

By the time the year’s out, he’ll have spent almost the entirety of 2017 and 2018 taking his third LP proper, This Old Dog, around the world; this is his second visit to Manchester in that time and his biggest show here yet, with the 5000-capacity Victoria Warehouse long since sold out – happily, there’s no repeat tonight of the overcrowding issues that have plagued the unloved venue over the past couple of years. The show is to celebrate the tenth birthday of local promoters extraordinaire Now Wave, who have put on every single Mancunian DeMarco gig to date, from his first appearance at The Deaf Institute supporting DIIV nearly six years ago to last year’s sell-out at the Academy, an attendance still dwarfed by this evening’s.

On paper, then, this is a carefully-curated celebratory show, with an extended line-up and late curfew, but in truth DeMarco has packed the place out on his own. The undercard is a peculiar affair, with the Canadian’s tourmate Jackie Cohen afforded a last-minute slot; her lo-fi, genre-bending wonky pop complements the headliner neatly, as do the 70s stylings of local boy Aldous RH, who delivers a set so laid-back that it’s practically horizontal. The main support, meanwhile, comes from the highly divisive Orange County duo The Garden, who oscillate wildly between doomy hip-hop, vicious punk and what’s probably best described as a thoroughly dystopian take on synth-pop. It’s nothing if not a spectacle.

Around four years ago there was, for a short time around the release of his breakthrough record Salad Days, a weird sort of lull at Mac DeMarco shows, particularly when it came to audience enthusiasm. It can probably be blamed on a combination of long-standing fans feeling disenchanted at his swift rise to large rooms, and newcomers being disappointed that they weren’t being provided with the DeMarco that his meme-worthy internet presence promised – the one that would think nothing of covering U2’s Beautiful Day in the nude with a drumstick hanging out of his arse.

DeMarco himself seemed to be struggling with the transition too, but by the time he was out in support of 2015’s mini-album Another One, he’d struck a happy balance, bringing that release’s low-key heartbreak out in the form of heartfelt singalongs whilst also finding room to, say, throw in a cover of Enter Sandman that involved him moonwalking across the stage in a Michael Jackson mask during an extended instrumental jam. Now that model has been followed through to what he presumably feels is its logical conclusion, which means that we get about an hour of original DeMarco and then the best part of 45-minutes of daft, karaoke-style covers.

The question is whether he actually needs to do that anymore; he started playing other people’s songs in the early days because he didn’t have enough of his own. Not only that, but the crowd laps up everything he throws at them from his own catalogue tonight, from deep cuts like Rock and Roll Night Club to genuinely affecting communal versions of This Old Dog and My Old Man, the latter reinvented to bring subtle, jazzy piano to the fore. The big hitters, meanwhile, invite veritable roaralongs; the crowd make a mockery of the smoking ban when he drops Ode to Viceroy, a love letter to his preferred brand of cigarette, whilst Cooking Up Something Good and Freaking Out the Neighbourhood both capture the giddy, freewheeling nature of their studio counterparts.

After an extended take on customary set closer Still Together, though, we descend into a black hole of silliness. Guitarist Andy White has done most of the talking between songs tonight, and now steps front-and-centre to compère a karaoke section that begins with Aldous RH returning to handle lead vocals on Killing in the Name and Heart-Shaped Box. White then takes the mic himself for a hat-trick of Misfits covers – Hollywood Babylon, Where Eagles Dare and Hybrid Moments – that are completely lost on a crowd made up primarily of the younger end of the millennial scale and the older side of Generation Z. In between, he continues to push his anti-fascist platform for a spoof run for the Manchester mayoralty. The nadir arrives when drummer Joe McMurray emerges from the kit to take on vocal duties on Red Hot Chili Peppers’ Under the Bridge and in doing so swiftly confirms that there’s a reason he doesn't normally sing. It does, at least, give DeMarco something to do as he sits in for McMurray – he’s spent the best part of the last half hour standing off to the side of the stage, swigging beer and looking slightly vacant.

And there’s the frustration – the guy had spent the entirety of the previous hour being received like a bona fide rock star by the crowd. Why sideline himself in favour of comedy schtick that is now tired to the point of exhaustion, especially when he could quite comfortably have played another three-quarters of an hour of his own material? When the covers come at the cost of Blue Boy, Brother, Passing Out Pieces, Goodbye Weekend, Let My Baby Stay, Baby’s Wearing Blue Jeans, A Heart Like Hers, and Still Beating – and you could easily go on – there really is no justification for it.

There’s a brief encore, although only at the demand of the hardcore down the front after the place has half-emptied – the crowd thinned noticeably and steadily throughout karaoke hour. DeMarco returns with keyboardist Alec Meen for a tender take on This Old Dog closer, Watching Him Fade Away, which describes his conflicting emotions at seeing his estranged father gravely ill. It’s gorgeous and serves as a sharp reminder that DeMarco thus far has always come across like that one kid everybody knew at school, who seemed like the class clown most of the time but always seemed to come up trumps when the exam results were out. Maybe he’s kicking out against the fact that probably every single review of This Old Dog praised him for his maturity and, if so, it’s a shame, because he doesn’t need to. Two hours of pure DeMarco would have been raucously fun. An hour of him and 45-minutes of frat-boy antics – less so.