So hooray for this work by the American composer Daron Hagen and the Ulster poet Paul Muldoon. It is billed as a "nightmare cabaret opera", lasts a painless hour, was premiered last year in New York, and is a neat find by Ireland’s Opera Theatre Company, which is taking it on a short tour of the Republic before bringing it to Britain next year.

Sassy libretto and music fool about happily with genres. Two retired IRA boneheads, Taco and Dumdum, living illegally in New York, are pursued by Immigration and by two renegade MI5 officers. As they change planes at Las Vegas, the INS agent Doll tricks them into thinking they have won a free day on the tables, and sets them up with Vera, a transvestite lapdancer past his prime who Taco falls for.

It’s about dawning self-awareness and coming to terms with the past, and it raises plenty of piquancies without getting heavy. You wish you could hear more of the words: Muldoon’s libretto is anyway dense enough for a spoken play and should probably be cut by about half — it’s impossible to follow his long paragraphs, however nicely constructed, and then you can’t hear half of it. It’s not a problem of texture or scoring.

Hagen’s music, smoochily played by a cabaret quartet, blends idioms — neo-Gershwin, jazz, soft rock, Broadway — with soaring melodies that send the characters looping off in arias of self-revelation. He has a gift for pastiche and musical surrealism as well as a distinctive voice for moments where words and music coincide. If Vera feels somewhat inconsequential and anecdotal there is a reason: it is the central act of a planned full-length opera.

As the pair (Alan Fairs and Eugene Ginty) stumble through a cleverly painted Vegas their plight is commented on by a chorus of airhostesses and showgirls who do the operatic impossible of both looking and sounding good. Annilese Miskimmon directs with pace and wit, Linda Dobell moves everyone around brilliantly, and the set is neatly done. Jonathan Peter Kenny, as Aladdin Sane-lookalike Vera, and Charlotte Page as Doll stand out among the singers.