Break a leg - When is it ok for popstars to cancel a gig?
AS ONE Direction fans mourn the cancellation of a gig in Belfast, we take a look at some of the most bizarre illness and injuries to befall musicians before, or during, a performance.
The band rescheduled last night's concert to Friday October 23 after Liam Payne was unable to perform due to a mystery illness.
The SSE Arena, where the band was due to play, has had some near misses concerning gigs being cancelled in the past.
In 2008, Boyzone singer Keith Duffy was rushed to hospital suffering an allergic reaction after having eaten a bag of nuts. Bandmate Shane Lynch said of Duffy’s severly swollen arms and legs that they looked like “something from the Elephant Man”.
It looked like the band might miss the start of their reunion tour in Belfast's Odyssey Arena, but Duffy recovered in time to perform.
Last year, Robbie Williams said he was in agony after performing a show at the arena in June.
"The day after Belfast was spent in bed with it completely spasming – like toothache under my shoulder blades," he said at the time.
"But one thing's for sure – the show must go on, and it will."
Further afield, there are plenty of times that legends of music battled injuries both mundane and bizarre, but continued with the show for their fans.
Halfway through a 2004 concert in Oslo, David Bowie sustained a bizarre injury when a lollipop thrown from the crowd became lodged in his eye.
After disappearing backstage to have a roadie remove the offending lolly, Bowie carried on to finish 27 songs in two hours and 20 minutes.
Foo Fighters frontman Dave Grohl may have taken messages of "good luck on stage" a bit literally when he broke his leg during a gig in Gothenburg, Sweden.
Ever the professional, Grohl returned from hospital several hours later to finish the gig in a cast.
One Direction's Niall Horan didn't let a fracture foot stop him performing either and appeared on stage in a cast last month.
Edward Grimes, one half of Jedward, also struggled on with their set after breaking his leg on stage in July 2010.
Enrique Iglesias sustained a bizarre injury during a concert in Mexico in June.
The singer sliced his fingers open after grabbing a drone that had a camera attached to it.
Iglesias required reconstructive surgery on his hand afterwards, but remained on stage for another 30 minutes following the injury.
There are some cases however where the show must be cancelled, sometimes for a very good reason and sometimes for a ridiculous one.
Michael Clifford, a member of Australian boy band 5 Seconds of Summer, escaped serious injury in June 2015 when his hair caught fire during a gig in London’s SSE Arena.
The show was cancelled after the 19 year old sustained burns to his face.
Never a woman to ever be described as conventional, Icelandic singer Bjork cancelled tour dates in both 2008 and 2012 due to an ‘inflamed vocal cord nodule’.
A specialist doctor advised Bjork to practise stretching exercise and rest her voice to avoid permanent damage.
A ham sandwich forced singer-songwriter Neil Young to put off his planned tour of Europe in 1997.
He sliced the tip of his index finger while cutting the sandwich.
“I’d have eaten the thing in one piece if I’d known that cutting it in half would jeopardize the tour,” Young said following the cancellation.
Yet, there are some 'life-threatening' situations where musicians must rest and recover and not even attempt to perform.
For example, James McElvar (19) of Scottish boy band Rewind, was told he was "lucky to be alive" after collapsing with heat exhaustion on a flight in July.
McElvar was wearing all the clothing he had with him - four jumpers, six T-shirts, three pairs of jeans, two pairs of jogging bottoms, two jackets and two hats - in an attempt to avoid paying Easyjet's £45 extra baggage fee.
Country legend Johnny Cash struggled with drink and drugs throughout his career, but an encounter with an ostrich nearly ended it all.
One of his pet ostriches attacked him in 1981 and he believes he would have died if his belt "hadn't been good and strong".
With one blow the ostrich managed to break two of Cash's ribs and 'rip his stomach open down to his belt.'
"Frankly I got off lightly," Cash said.
"As it was, he knocked me over onto my back and I broke three more ribs on a rock - but I had sense enough to keep swinging the stick, so he didn’t get to finish me. I scored a good hit on one of his legs, and he ran off."
Well, Liam Payne, what's your excuse then? It better be a good one...