Miss Atomic Bomb celebrates the sub-culture that grew up around nuclear tests in 1950s America. The citizens of Nevada would throw parties and stage barbecues to coincide with the latest nuclear detonation in the desert. This musical has a lot going for it. The melodies are strong, and well sung. The high-kicking chorus lines are easy on the eye and the show has a zippy, innocent spirit. But the storyline gets sidetracked in a mass of contradictory directions. The main theme follows a homesick farm girl who becomes involved with a runaway soldier whose brother runs a Vegas nightclub where a beauty contest is being held that the farm girl hopes to win. Other meandering subplots concern a hunt for a spy, a gang of psychotic mobsters and the disappearance of a stand-up comic whose hair keeps falling out.

The show’s star, Catherine Tate, has taken a minor role that conspicuously fails to capitalise on her gifts. Tate is a virtuoso caricaturist who specialises in distortions of accent, speech and costume. She can do anything from a lesbian countess to a homeless Rada graduate or a Nobel prize-winning Scouser. But her inspiration is Britain and the teeming plenitude of our social layers and disparate regions. Her character here is a generic American redhead with a silly name, Myrna Ranapapadophilou, and a twangy Southern accent.

Myrna’s motives are ironically light-hearted. She’s a dressmaker hired by the army to adorn human dummies used in the nuclear tests. And she has a fake romance with a gay hotelier which turns into a marriage of convenience. These details may be glibly amusing but they’re fatal to the show because they overlook the essence of musical theatre. Great musicals acquire their potency by inviting play-goers to commit themselves, at some deep and unspoken level, to the destiny of their characters. But Myrna is just a winking, sugary dollybird with no emotional sincerity and no mission to fulfil. She’s less a figure in a musical than an idea in the mind of a parodist. And if the writers can’t take the characters seriously how can anybody else?

The casting of a British star in a show with a strong American flavour suggests a yearning for a West End transfer in the summer. But there’s a snag. The show derives much of its macabre humour from jokes about mushroom clouds and radiation sickness. At the end, a spume of light grey flaky stuff settles over the audience from on high: nuclear fallout. One atomic mishap anywhere in the world and this joke will take on a very different complexion. Investors may not fancy a risk like that. And it’s worth noting that the show’s creators, like so many aspirants in this genre, have broken one of the cardinal rules. Base your musical on an existing novel, play or film with an established fan base. Doing otherwise is like entering a yacht race without a mast.

The London stage has all but ignored the spiritual birth of the Irish republic whose centenary is upon us. Playwright John Dunne, a Brit of Irish extraction, is well placed to study the events with a clear head and an even hand. His drama examines the impact of the rebellion on the community it purported to liberate. The seizure of the General Post Office in Sackville Street (now O’Connell Street) was plotted by a smattering of outlaws led by James Connolly, a Marxist hothead from Scotland, and the idealistic youngsters Michael Collins and Padraic Pearse.

The play reveals that popular support for the rebellion was patchy at best. Dubliners in 1916 were British subjects and many were happy to affirm their loyalty to King and country. A garrulous housewife, or ‘shawlie’ in Dublin dialect, mocks the rebels as ‘German sympathisers’. She fears that the rebellion may cause her to lose her ‘separation money’ (payments made to the families of Irishmen serving in the trenches). Many Dubliners used the rebellion as an excuse for thieving. We see the manager of the Metropole Hotel worrying that thirsty anarchists will break into his wine cellar. A Catholic priest is shown denouncing the militants but stopping short of excommunicating them.

The Brits are portrayed as cunning and seasoned authoritarians. The army commanders were holed up in Dublin Castle and as they planned their counter-attack they knew exactly how much was at stake. Not just Dublin or even Ireland but the entire edifice of imperial power. Failure to crush the Fenians would embolden potential rebels in every colony from Guyana to Singapore. When they retook the GPO their military aim was twofold: to destroy the uprising and to create as few martyrs as possible. They got it half right.