But Bret Easton Ellis's novel about a 1980s yuppie Manhattanite who is also a serial killer has been brought to the musical stage. Roberto Aguirre-Sacasa (Riverdale) adapted it and Tony Award winner Duncan Sheik (Spring Awakening) wrote the music and lyrics with 1980s hits from Phil Collins and other artists also incorporated.

The Australian production is scheduled to come to Canberra in late June, depending on coronavirus restrictions.

Its director, Alex Berlage, says he gets one of two reactions when he mentions the show. And they mirror his own initial responses.

The first is something like, "What in the world - how can that be a musical?"

But, he says, people who have read the book respond more positively. American Psycho has meaty ideas, which Berlage likes to have in any theatrical undertaking.

"It's the story of a human being in an existential crisis and what it means to live in a capitalist system."

The piece, he says, is "a daring critique of what we have become as a society" through self-obsession and greed.

And the story's themes of sexism and misogyny have made for intense discussion among the creative team. Berlage says he's taken the story and "subverted it" by approaching it through a feminist lens.

Additionally, he says, alluding to a notorious passage in the book, "There are no rats in this production."

What constitutes a weird musical is inevitably subjective. It's not necessarily about a show's artistic or commercial success: it can be acclaimed or derided, a hit or a flop. It's not about the talent involved either: some big names have taken their creativity to strange places.

Perhaps Berlage's first reaction to American Psycho - how can that be a musical? - is one useful measure.

And so is Canberra director Jim McMullen's distinction between "weird and accessible" and "weird and inaccessible".

If people enjoy a show, the oddness doesn't much matter.

While what constitutes a weird musical is open to debate, American Psycho surely qualifies as one. This is no boy-meets-girl love story.

Heathers: the Musical IS a boy-meets-girl love story, but not the conventional kind. Based on the cult 1988 movie, it's about a high school girl whose relationship with mysterious outsider JD turns increasingly dark as they start murdering the popular kids.

Another unlikely musical dealing with murder is Thrill Me: the Leopold and Loeb Story. Stephen Dolginoff's two-person show is based on the true story of Nathan Leopold and Richard Loeb, two young men whose obsessive relationship and desire to prove their superior intellects led them to try to commit the "perfect crime" by kidnapping and murdering a 14-year-old boy. The show even manages a (fictional) twist.

While Cats became a huge hit, there was always something decidedly odd about it - even before the 2019 movie version that some people viewed under the influence of various mind-altering substances for added strangeness. The show has a bunch of people costumed as singing, dancing cats doing various performance turns in the hope of being the one selected to ascend to the Heaviside Layer.

Berlage says, "In my opinion it should never have been made - it's an example of a piece and concept that don't go anywhere.

"It's as though a group of theatre people were sitting around and one said, "Hey, why don't we do a musical about a group of singing cats?'

"Nobody really thought any further than that."

Veteran US theatre director Hal Prince once said in an interview that when Andrew Lloyd Webber first played the score of Cats for him, "I looked at him curiously and said, 'Andrew, I don't understand. Is this about English politics? [Are] those cats Queen Victoria, Gladstone and Disraeli?'

"He looked at me like I'd lost my mind, and after the longest pause said, 'Hal, this is just about cats.'"

There are plenty of other weird shows in the history of musical theatre. Another Canberra director, Chris Baldock, agrees that Cats is strange.

"So is Starlight Express."

The latter, another Lloyd Webber show, has been frequently produced and frequently revised.

As Lloyd Webber might have said to Prince, it's just about trains. Specifically, it's about an obsolete steam engine running against modern trains to impress a first-class carriage. The cast perform on roller skates, often singing and skating at high speed (which has led to many injuries in productions).

Berlage says Starlight Express "reinforces gender stereotypes" with its characterisations of the "male" and "female" trains. And, as noted, he prefers his offbeat shows when they have something to say.

Urinetown is one such musical, a self-aware show referencing musical theatre conventions and forms and other pop culture. But it has a storyline of its own and something to say. A decades-long drought has led to strict control of resources: all lavatorial activities must be performed - and paid for - using public toilets owned by the megacorporation Urine Good Company.

Berlage says, "It's such a wacky idea" - but the show mixes its humour with weighty themes such as corruption, environmentalism and class.

McMullen finds another unusual show to be "awful" and "over the top".

He asks rhetorically, "Why the hell would you want a musical of Jerry Springer?"

Grandiloquently titled Jerry Springer: the Opera, the British musical was, like its talk-show inspiration, controversial, full of profanity, alleged blasphemy, and spectacles such as a line of singing, tap-dancing Ku Klux Klan members.

Another show McMullen felt was unnecessary was Octomom: the Musical.

"Why the hell?!"

Closer to home, he's similarly dubious about the idea of Shane Warne: The Musical.

An offbeat show more to McMullen's liking is the Stephen Sondheim show Merrily We Roll Along, which, like its source play, was told backwards, starting in the jaded, unhappy present and ending in the past when its characters were young and idealistic.

Like Merrily in its original production, some gambles with strangeness are swift flops - and not all get the renewed attention Sondheim's show did.

Among the freaky failures are Into the Light (1986), about discovering the truth about the Shroud of Turin and Via Galactica (1972), set in the year 2972. In the latter, Earthlings are now all blue-skinned test-tube babies to eliminate discrimination. A group of non-conformists are living on an asteroid and kidnap a space garbageman to deepen their gene pool.

The latter had a score by Galt McDermot, who'd enjoyed a big hit with Hair. "The American tribal love-rock musical", as it is subtitled, seems weird to Baldock.

"We're so far removed from it: it's quite psychedelic and a little bit inaccessible to some people."

But despite this, and its slight storyline, he says it is still "very powerful" with its make-love-not-war theme. Whether it will survive the passing of the baby-boomer generation remains to be seen.

Horror properties don't always make successful musicals (the well-known adaptations of Phantom of the Opera and Jekyll & Hyde feel more like melodramas with horror elements). Perhaps scariness and singing just don't mix well.

Lestart, an Elton John-Bernie Taupman show based on Anne Rice's Interview with the Vampire, came and went. Carrie: the Musical - based on Stephen King's novel about a bullied high school girl who wreaks revenge through telekinesis - was also short-lived in its original Broadway run but was notorious as a bomb with many technical problems. One of the songs was Out for Blood, about killing a pig.

Financially, an even bigger Broadway flop than Carrie was Dance of the Vampires. Based on a Roman Polanski comedy horror film also known as The Fearless Vampire Killers, features composer Jim Steinman's Total Eclipse of the Heart, a hit for Bonnie Tyler in the '80s.

McMullen says, "The version of it is atrocious" and calls the show "godawful".

It has, however, had many European productions and many rewrites.

The Who's Tommy and Pink Floyd - The Wall, both inspired by albums from The Who and Pink Floyd, respectively - are also decidedly strange. Tommy is a deaf, dumb and blind "pinball wizard" and Pink is a rock star driven insane by the death of his father who doesn't want to let in the outside world. The familiar albums no doubt smoothed the path for the shows.

Many other strange musicals have been produced - and they are still coming.

Last year, Mommie Dearest: the Musical premiered.

It's based on Christina Crawford's memoir detailing her fraught relationship with her mother, movie star Joan, depicted as an abusive alcoholic.

Flashing back, the 1989 movie comedy The Tall Guy showcased Elephant!, a fictional musical based on severely deformed Joseph "the Elephant Man" Merrick. It was supposed to be an Andrew Lloyd Webber-ish spoof, but a few years ago Laurent Petitgirard composed a serious opera, Elephant Man, about Merrick.

Now, it would not be a surprise if a musical version of the story eventuated.

Is there anything that can't be musicalised? It seems not.

Apparently, as Cole Porter in a rather more conventional show put it, "anything goes".