Pirates of the Carabina is an informal collective of alternative circus performers who first came together at the Glastonbury Festival two years ago and returned there this year, attracting a big audience, I'm told, even when the Rolling Stones were strutting their stuff.

You can see why. Their new show Flown is a mix of acrobatics and heavy metal rock music, with a folk rock "Glasto" element that reeks of the old Woodstock spirit and suggests a boho lifestyle that only this form of theatrical expression could satisfy. As far as it goes, it's fine.

But how far is that, exactly? There seems something terribly random about it all, not properly constructed, though the inbuilt mishaps – a falling light rack, a flying acrobat caught up in her own ironing board, another stranded perilously (and hilariously) in her own silken wrappings, are very well worked.

There's a steel gantry framing the antics in the Underbelly, a lot of red swag, and a stage-manager/emcee who wanders around looking like a disgruntled version of Sandi Toksvig.

Enjoyable in it its way, Flown also seems like a routine compilation of circus and physical theatre skills without a defining stamp or personality of its own.

Flown continues at Underbelly, Bristo Square ​until 26 August (not 6, 13, 20)