This anthemic outpouring was the genial conclusion to Jen Edgar’s Happy Happy Happy (***), a promenade through some whys and wherefores of what makes us feel glad to be alive that could -- with room to expand on its ideas and installations -- become a five star experience for audiences.

Within the context of a Happiness Clinic (with echoes of a hands-on museum about it) Edgar and her collaborators laid out the good-hearted beliefs of Mike, the guy whose contented life was the bedrock of the Clinic. If Sartre thought Hell was other people, Mike reckoned folk -- family, friends, a community like a choir -- were the root of happiness. Music, choccie biccies, witty design elements you could play with and text that melded loveable whimsy with scientific observation, plus that Bowie finale -- I’d be happy to see this one developed further.

Has motherhood made Lucy Gaizely happy? Well it’s certainly given her some blisteringly fierce material for Eggshells, Sweetheart? (****) . This isn’t about her children per se, but ‘motherhood’ and the rules and expectations that society dumps on post-partum women.

These have left Gaizely feeling at bay, inwardly thinking ‘Courtney Love -- rock chick’ as she waltzes with her ironing board or offers us cuddles, in between questioning why her individuality seems to have been superceded by the tag of ‘mother’.

Gaizley always was a wonderfully uncompromising, visceral performer: those qualities haven’t been drained away, like the breast milk she expresses and then pours into her cake mix. If anything, she’s gained a lacerating focus on how easy it is to lose youself in stereotypical behaviour by trying to be what convention maintains is a ‘good mother’. There’s anger, defiance and rebellion aplenty, but there’s also a touching poignancy, not least in a washing-line of big knickers that spell out Yes I Am Still Present.

Kate Baird begins her solo show, Is It Because... (***) with chatty confidences about personal memories.

She jollies us into closing our eyes for a memory-retrieval exercise and it’s still like a game. But Baird pulls a fast one on us when she necks down the alcoholic drinks associated with significant times in her past, shifts the piece into painful, confrontational mode and rips aside the pleasantries in a bravely raw exposure of how memories can haunt and hurt.

John Cavanagh’s memories and consummate skills -- as a music-maker, DJ, mimic and more -- power up what is, in a way, a quirky, oddly poetic love letter to radio broadcasting. Maria Gil’s production Pirate Radio (HHHH) reached out beyond the Arches -- it was streamed live, on Radio 6 International -- but if you were there, as the ‘studio audience’ you witnessed and interacted with the rituals of flying the control desk, and enjoyed the sly joke of Cavanagh switching chairs and voices to interview himself in a separate personna of a Dundee folkie who’d embraced shamanistic chanting in the wilds of Russia. Pure magic, and a reminder of how our ears can lead our imagination in strange and wonderful directions.

Liars proved a mischievously apt name for the group who led us into Post Show (***) , a discussion about a play that didn’t exist. On one level it was a larky spoof of the often po-faced and worthy exchanges that keep loyal audiences, and press-ganged cast members, from the bar. Audience questions (carefully planted) ensured a flow of hilariously ridiculous responses.

But gradually another less farcical strand emerged that dissected the processes of theatre-making -- How far should a director push an actor in search of ‘the truth’? How far should an actor go simply because they need the job? And if some of the scenarios nudged the piece towards bizarre wackiness, the format and intentions had the potential to stimulate a real, and meaningful, debate about the issues.