Down the derelict end of a shopping street in Glasgow's Merchant City there is a narrow alleyway, cobblestones and corporate bins. Risk it, make your way around the parked van and find a prised-open fire exit. The stairs inside are carpeted but worn, more ground-in dust than weaved fibres. Up, up, up you go and through a door and you'll find the Britannia Panopticon - "the world's oldest surviving music hall".

Surviving is probably the most apt of terms. Crumbling rafters, exposed bricks, peeling paint, hungry ancient fleas. Stan Laurel did his very first turn and tumble here. All the old ticket stubs and Edwardian flyposters that the caretakers have found malingering have been framed up like a local historical society display. An eager festival usher proudly tells me of the dozen or so gentleman's trouser fly buttons they found up in the gods unclaimed. Ripped from their stitching by careless prostitutes in a rush to get on with that long forgotten night's job at hand.

But the stage! The stage has an unmistakable musty, authentic magic. The show is set to start and we get a lengthy fire safety announcement from a keen volunteer. With well-rehearsed gags and mumsy enthusiasm it is hard to tell if this is a part of the show or a city ordinance. I expected the Grubby Little Mitts to be a sketch duo of the theatre grad ilk, not a pitch perfect Lynda Bellingham. One half of Laurel & Hardy is a high enough bar but now a fire drill is smashing it before our acts have even stepped on stage!?

Luckily, Grubby Little Mitts' latest touring hour Hello, Hi bowled me over. More than lived up to their auspicious, if rack and ruined, settings. A boy girl combo with strong chemistry and dank leanings. The weirder or more sexualised their skits, the better. And even when the formidable hit rate wobbles, Rosie Nicholls knows exactly how to point, bow or wink to putt the end scene into the hole of applause.

Two absolutely puerile takes on Singin' In The Rain bookend the hour in spectacular transgression. Sullivan Brown's recurring character Father Cluck (a horny rooster of dubious carnal knowledge) has a litany of catchphrases you welcome with every cheery / bleak return. A ludicrously repetitive sales pitch about bread will sear itself into your memory. There's existential cringe, near constant horniness and a gloriously accurate sketch about how frustrating cat ownership can be... with a fist of a twist. Sinister imagination stretchers throb behind a naive facade.

Plummy sketch comedy isn't my wheelhouse but Grubby Little Mitts worked me over good. Plenty of absurd belly bellowers here and the quality of the gags only increased as we got more and more comfortable with the pair's attractive, sturdy dynamics. Glasgow was the first date of their tour and if they come near you then you best grab the Mitts with both hands.

Smutty Letters at the Riding Rooms was a change of gait. An LGBT cocktails and cabaret lounge with only a modicum of distance between the stage, the tech booth, the front door and the bar. Non-negotiable intimacy was probably the best environ for this gently amusing show.

Comedy festivals attract a broad spectrum of genres and Smutty Letters is closer to literary tease than chuckle fest. Our hazy voiced host Revolting Rosy reads us love letters from the past. Their curation for this edition picks and chooses mainly from the moments when straight white men tipped over into horny humour. We get Bukowski getting distracted by his equal ardour for a kitchen appliance as for his conquest and verbose cad Patrick Leigh Fermor's jealousy of the dose of crabs he possibly could never have given a distant paramour.

Whether by famous people, or long-passed family members, Revolting Rosy's selections and recitals are spot on. As is their delicious burlesque attire: candy coloured whalebone corset, labia shaped fascinator and a foxy red boa to match their hair. Our affirmative and accomplished master of ceremonies made the night. She even engages in a free-writing workshop to wrap things up. We get to essay our own ribald prosaic biro devotions. Stationery provided. Fear not, audience participation avoider! There's no pressure to share your work and Rosy offers us a variety of discreet solutions to hide or destroy the scribblings. Smutty Letters proved a Sunday evening treat and probably a fine "third date" destination.

If you like your stand-up down and dirty (and you know I do) then McChuills is the place to hit. Built into two railway archways and with those kinda local old soaks propping up the bar that no manner of Northern Soul themed refurbs are ever gonna turf out. The mucky odour of the kip reminded me of all the tiny moshpit gigs of my youth. No complaints... I saw them give free hot drinks to an unhoused character in need. He knew the McChuills gang to be the right people to ask. It felt more inclusive than a million middle class gentrified spaces that try a lot harder for people who'd be welcome anywhere that takes money. I saw a perfect set up for underground, authentically 'punching up' comedy.

Enter Richard Brown & Mekkin Roff, in Trauma Jokes For Damaged Folks. Icelandic-American Roff goes in hard with no sweetness about her. Good... if you are intending to bruise your audience straight out of the gate with acidic takes on school shootings and dad's cancer then there's no need for sugar coating. Okay, she does do a curtsey after a particularly abhorrent topper.

Roff's slow, spaced out timing suits her nasty. She has an armoured patience to let a damaging line dig in... and they are uniformly wounders and sensibility shakers. She lashes out at everything worth taking down. The only time she bullies herself is when she rattles off the litany of initials for all the mental illnesses she has been diagnosed with. What am I meant to do with that? You dare not laugh at her with so many potential triggers. Luckily there are brilliant jokes about breastfeeding and her inheritance. The only other stumble is her experiment with ukulele comedy. She is no Tim Minchin and her take on feminist men goes on a little longer than her cuck soy boy lovers would appear to.

Glasgae cult favourite Richard Brown feels mellow... light even... by comparison but only in the early rounds. He did a themed gig recently and proudly repeats his Catholic Saint-based homework, projecting it up via PowerPoint. I kid you not. Considering he cobbled it together in a rush, there's a heavy cackle body count that comes with each slide. Silly visual laughs and blasphemous sight gags.

Once it's just him, a mic and a notebook, Brown's agile, abrasive mind goes into full flight. Risky, but with that invincible success rate most misanthropes forget to aim for. He takes a healthy pass at people hung up on pronouns. He gives everyone the image of their dear old grandmother having once been finger banged by the callous digits of a real working man. Even his 'innocent' cake stuff is decorated with a censored word that'll get them tutting at golf club socials across the central belt. Not that Brown is getting booked for that type of gig by any promoter in their right mind.

For every challenge-seeking comedy fan bellowing loudly at McChuills, there was another shell-shocked face looking like they had paid good money to eat shit for their Sunday night out. Buyer beware, the show ain't called Trauma Jokes For Damaged Folks because everyone will agree with his opinions on the Royal Family or her ideas on what sexual objectifications are acceptable. Glasgow still has its bite. And Brown is swinging at a place of genuine social commentary. His hardcore stuff isn't a new act churning out shock imagery. He sincerely cares and intelligently executes the modern day traitors on his hate list.

Grubby Little Mitts: Hello, Hi is touring the UK until Tuesday 2nd April.

Next year's GIFC will be back on all across the city in March 2025.