The idea that musicals are brimful of high kicking chorus lines and glitzy optimism must surely have had its throat cut a la Sweeney Todd by now; or been beaten to death as happens in Urinetown, or electrocuted - a fate agonizingly dwelt upon in The Scottsboro Boys.

In Sondheim's little-revived 1990 musical - the darkest of the lot - the chair is just one form of premature death. Most get their brains blown out. The victims are American leaders; the perpetrators, that slice of unhappy humanity who think the antidote to their woe lies in killing the leader of the free world.

The action takes place in a nightmarish and dilapidated fairground. We enter through a gaping clown's moUth. To step inside Jamie Lloyd's shadowy production is to enter the mind of the embittered and resentful. All eight of the successful and (known) unsuccessful killers of America's lunatic fringe are represented here: from Lincoln's murderer John Wilkes Booth (Aaron Tveit) to Sara Jane Moore (Catherine Tate) one of two women who attempted to kill Gerald Ford. And then to that tally, the show adds one more – LHO (Lee Harvey Oswald) the man who shot JFK.

John Weidman's book skilfully takes on the impossible task of unifying these history-changing footnotes. Each have their own psychosis. Andy Nyman's jittery Charles Guiteau killed President Garfield in 1881 because he wanted to be ambassador to France, Tate's suburban mom wanted to impress her hippy friends, while in 1974 unemployed tyre salesman Samuel Byck – played by Mike McShane in a filthy Santa Clause costume - failed in his conspiracy to kill Nixon by smashing an airliner into the White House and thereby forcing the world to pay attention to a man who felt utterly overlooked.

Sondheim allocates each a sublimely sardonic song. Most are accompanied with light irony and sweet melody by Jamie Parker's banjo-plucking minstrel. To Charles Guiteau's "If I am guilty, then God is as well," Parker's minstrel replies, "But God was acquitted and Charlie committed...." He's the show's one voice of sanity - a well-adjusted antidote to the seething resentments he serenades.

With the song Another National Anthem this motley lot have a banner under which they can gather.

Witty and light though it is in an ironic, optimistic musical kind of way, the grievances and psychoses contained within serve as a chilling warning that one day Sondheim's incredibly daring musical is going to need updating.

Hope

Royal Court

★★★★✩

V Just for fun, imagine how the pitch to Jack Thorne's play would sound to a commercial producer. "It's about balancing a council's budget." Yet it turns out to be gripping stuff.

Our hero is recovering alcoholic Mark the good-hearted deputy leader of a Labour council. His instinct is to save every public service squeezed on the one hand by government cuts and on the other by the law which prevents councils from raising enough taxes.

Yet this is not old-school left-wing agitprop as one colleague assumed during the interval. The offstage villains of the peace are the banks, Cameron and Osborne, it's true. But in the second half of the play old-school former council leader George (Tom Georgeson) declares that the Prime Minister and Chancellor have "remade the British economy.

Not in the way I'd like but by their own standards they've kicked the ball out of the park." It's a speech that in many ways sounds the death knell for Labour, which as George puts it, is "a party that doesn't fit the modern world."

Tom Scutt's design of a town hall's drafty interior serves as a convincing setting for personal and political plots. And Paul Higgins as Mark captures the world weariness of man fighting a losing battle. Though never without hope.