Hayes Theatre Co, Sydney, September 19.

“I shall be remembered,” cries Charlie Guiteau as he dances his way to the scaffold, singing a plaintive hymn of his own devising. Charlie who? History can be cruel to those who seek to make their mark by whatever means possible. We may remember the effect of their actions but precisely who they were and the reason they did what they did? Not so much.

Stephen Sondheim and John Weidman’s Assassins (1990) throws together a motley band of successful and would-be killers of US presidents and assesses them against the unforgiving standards of American exceptionalism. “Everybody’s got the right to be happy,” the opening number asserts, by which is meant the right to be noticed, be taken seriously, make a mark, be someone, be famous.

The right to bear arms makes the pursuit of those goals just that bit easier. Some things never grow old. (Guiteau, by the way, was one of the winners, despatching James Garfield in 1881 partly because Garfield ignored his desire to be US ambassador to France.)

Assassins is explicitly set in a fairground shooting gallery, evocatively designed by Alicia Clements (set and costumes) and Ross Graham (lights) as a dark, seedy dump with touches of tawdry glamour. The action sits outside of time and place. Here, in a hallucinatory present, presidential murderers and wannabes from elder statesman John Wilkes Booth (Abraham Lincoln, 1865) to John Hinckley Jr (Ronald Reagan, 1981) get to explain themselves, mix and mingle a little and maybe get a little understanding.

Dean Bryant’s production of this rarely seen Sondheim comes very close to being great. The crack team includes a terrific five-piece band under Andrew Warboys’s direction and Andrew Hallsworth as the very fine choreographer. The cast couldn’t be better and the staging expertly walks the tightrope between black humour and coruscating anger and back again.

The themes have certainly not worn out their welcome. Like the tolling of a muffled bell, certain words repeat throughout Assassins. “Never, never, never.” “Nothing, nothing, nothing no good.” “No one listens.” “I am nothing.” Not. No. For all their delusions and misguided passions, these flawed souls have a powerful point about life’s injustices.

It’s just a pity Bryant doesn’t let their carnival masks slip more often. Assassins would be more potent for it. His Little Shop of Horrors, which premiered at the Hayes early last year, was pitch-perfect; Assassins occasionally less than that, including the final image, which offers an easy laugh but not a dramatically satisfying reason for being in a work that gives the deplorables their moment in the sun.

The extraordinary 11-member cast otherwise knocks it out of the park. Each one deserves nothing but superlatives. Kate Cole and Hannah Fredericksen form a wacky double act as Sarah Jane Moore and Charles Manson acolyte Lynette “Squeaky” Fromme. They each attempted to kill Gerald Ford in 1975 within three weeks of each other, as unsuccessful in handling a gun as Ford was in winning respect. Connor Crawford is the unnervingly self-effacing Hinckley, who shot and injured Ronald Reagan in an effort to win Jodie Foster’s attention.

Martin Crewes as Guiseppe Zangara (Franklin D. Roosevelt, 1933) and Jason Kos as Leon Czolgosz (William McKinley, 1901) make their anarchist firebrands worthy of our consideration and compassion. Justin Smith’s tremendously good Samuel Byck (Richard Nixon, 1974) is the epitome of madness masquerading as reason. “I’m talking, you’re listening,” he says. “It wasn’t supposed to be like this.” Well, that’s what they all feel.

Newcomer Maxwell Simon is impressive as the sunny balladeer who morphs into Lee Harvey Oswald (John F. Kennedy, 1963) and Bobby Fox’s Guiteau gets the big vaudeville song-and-dance treatment, nailing the number’s frenetic, “it’s showtime” gaiety. Appropriately though, David Campbell (the tightly wound, upright Booth) is first among equals. “The country isn’t what it was,” Booth sings in 1865 and his anguish echoes through the ages.

Rob McDougall gets the show off to a strong start with his laconic, sonorously sung shooting gallery proprietor and Laura Bunting is wonderful in Something just Broke, the song that finally turns the musical’s gaze away from the assassins and towards the ordinary lives they affected.

It’s powerful material despite the occasional clunkiness in Weidman’s book, particularly as Sondheim’s score is hugely effective, co-opting popular musical styles appropriate to each assassin’s era. Good luck with getting Hinckley and Fromme’s soft-rock duet Unworthy of Your Love out of your head.

Tickets: $70-$78. Bookings: hayestheatre.com.au. Duration: 1hr 45mins with no interval. Ends October 22.