There was a palpable sense of excitement in the Olympia Theatre last night, in advance of Imelda May’s first performance of Mother Of All The Behans.

And no wonder. To describe this as going outside her comfort zone as an artist is to put it mildly. Imelda had spoken in advance about trailing around the place looking like a mad woman, as she recited lines from the play to herself, trying to get them irrevocably into her head.

You can see why. This is a one-woman show. There is no one else there to bounce off or to step in to help if you suddenly find yourself lost and staring into space.

In fairness, Imelda isn’t entirely alone. Songs are sprinkled liberally throughout, and she has musical director Sean Gilligan there on piano, sometimes adding atmospheric music as she speechifies, and otherwise backing her superbly on the big songs.

But as a play, it’s a monologue, and so it is all down to Imelda. It opens with her in bed, and you kinda hope that she won’t stay there too long.

She doesn’t, and in a jiffy, director Peter Sheridan – who also adapted Mother of All the Behans from Brian Behan’s original 1984 biography – has her gambolling around the bed, which sits on on a raised plinth, with skittish enthusiasm. Is it only me who feels, Jesus, don’t fall off it Imelda, for fuck’s sake – you might break a leg? Literally!

There’s also a strategically placed screen, behind which Imelda can execute costume changes, which, at least some of the time, are played for laughs. As her appearance changes to mark different life stages, it is a device to make us aware that we are seeing, as well as hearing, the life-story of a woman who knew more than her share of heartache and grief as well as pride and joy in the Behan name and accomplishments.

The section on the family’s move from the inner-city to Crumlin is brilliant, with the new suburbanites more or less immediately longing for a return to the non-comforts of Rutland Street, whence they had been uprooted. There is, sadly, a new resonance to the play’s account of the travails of people who were evicted and forced to the periphery of city life. The old line rings true: the more things change, the more they stay the same, with fat cats thriving and citizens weighed down, left, right and centre, by the struggle just to survive.

But most of all, what we learn is the impact that 30 years of war had on ordinary working class people in Dublin – even the most intellectually ambitious of them, among whom, of course, the Behan clan ranked. From the start of the First World War in 1914 when the recruiting Sergeants went about their dubious business across the country, through the desperate family-busting horrors of the Irish civil war, and on to the end of the Second World War in 1945, it was always the working class who suffered the greatest indignities and losses. That much is hard-boiled into the way things operate.

There is some respite in the long run, as Kathleen finds room to boast of the enormous theatrical success that Brendan enjoyed, when she was taken to the theatre, in London I think, in a Rolls Royce and back in a Daimler. But, ultimately, there is more tragedy on the way. Kathleen was, as Peter Sheridan says in his programme notes, a feminist before the word was in anyone's vocabulary. She was ready to take on the world if and when she needed to, but someone else’s alcoholism is an impossible foe.

Imelda carries all of this drama off brilliantly. She manages the conversational tone of the writing superbly. The jokes land, and there is laughter on and off throughout. And there are times when you can be looking at her face, and see clearly the way in which emotions, thoughts and fleeting feelings are registered in her shifting expressions.

We knew, of course, that Imelda has a wonderful voice and could sing the phone book well enough to make you cry. Here, she has numerous classics to work with and she does it marvellously. There is the incendiary power of ‘Johnny I Hardly Knew Ye’. The wit of 'Miss Houligan's Cake’. Harry O’Donovan’s humorous Liberties meisterwerk ’Sweet Daffodil Mulligan’, also recorded by Lankum (Fresh fish!). ’The Auld Alarm Clock’. A glorious version of ’The Auld Triangle’. A heart-swellingly emotional 'The Laughing Boy' from Brendan Behan's play The Hostage. And, as a finale, the wonderful Dublin ballad we know as 'Molly Malone’.

I thought about saying that Imelda May doesn’t put a foot wrong throughout. But far more impressive is the fact that she goes way beyond just singing these songs. She lives them and delivers them with just the right balance of gusto and pathos. And, though it first hit the stage in the 1980s, she makes Mother of All the Behans feel like a play that was written specifically for her.

The final image of Molly’s inimitable ghost wheeling her wheelbarrow through the streets broad and narrow of the city Kathleen Behan, Peter Sheridan and Imelda May all loved or love, and the ancient cry of "Cockles and mussels” ringing out into the sky over Dublin seems like a perfectly fitting way to end what is a marvellous evening of theatre.

Catch it if you can.