Not for the first time, a cheap flight takes us from somewhere pedestrian to somewhere delightful. I found the first half of Fascinating Aïda's gig easy to admire but hard to love. The joke – mordant songs about modernity sung in old-school, West End Wendy-style – was too obvious, and too cheap, as if this female Flanders and Flanders and Swann trilling about "stiffies" and "John Thomases" were inherently outrageous. Then they sang their Ryanair-bashing internet hit Cheap Flights, which works in a different register. What's seductive about Fascinating Aïda was unlocked, and what's offputting didn't resurface.

It helps that the faux-Irish Cheap Flights is largely sung by founder Dillie Keane, who – by trying seemingly the least hard – is the funniest presence on stage. Liza Pulman provides the pipes: she sings, and beams, like she's stepped off the set of Salad Days. Adèle Anderson's arched-eyebrow demeanour is effective if familiar. Keane is the hangdog star, the opposite of ingratiating, her mischievous spirit barely hidden behind a facade of exhaustion and cynicism. What's great about Cheap Flights is that she rustles up such naive innocence at the start – flights for 50p! – before disillusion rears.

This is more effective than their prim and jaunty, Radio 4-friendly ditties lacerating new age living and tax-dodging bankers – although "He's so fundamental/ he hasn't seen Yentl", of an Islamic terrorist, is surely unbeatable. The trio are best when that default setting is swerved, in favour of absurdism ("An orangutan is having my baby") or hip-hop. (Sounds dodgy, but it's fun.) Or, indeed, songs that aren't amusing at all. Having made us laugh, Keane and co are perfectly positioned to thrum the heart strings, which they do with a closer about the passage of time and the passing of friends. Stylistic foibles aside, there's some lovely songwriting here – comic and otherwise.

What have you been to see lately? Tell us about it on Twitter using #GdnReview