It appears straightforward: employ a proven, high quality vocalist to belt out a country's national anthem before a major sporting event.

What could possibly go wrong?

As we saw on Sunday, it's not as easy as it looks, when American Crystal Collins took the microphone in Denver to sing both God Save The Queen and God Defend New Zealand before the rugby league test.

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Mostly the national anthem goes off without a hitch but sometimes things can go awry.

Most anthems pass with minimal comment or criticism, the singer doing his or her job well as the crowd and teams join in before the sporting action starts.

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But, sometimes, anthems can go bad. Think Roseanne Barr's appalling screech of the Star Spangled Banner in 1990 before a San Diego Padres baseball game. So infamous, it warranted a 25-year anniversary story in 2015.

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The Silver Ferns sing the national anthem ahead of the Taini Jamison Trophy match against Jamaica in March.

And in February when Fergie of the Black Eyed Peas apologised for her performance at the NBA All-Star game which was described as a "sultry, bar-room rendition" and, less kindly, the "worst anthem ever".

Here's some examples closer to home when, for one reason or another, the anthem hit the headlines almost as much as the match itself:

Skylla Halstead - Tall Blacks v Australia basketball in Melbourne, 2007

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The Tall Blacks, pictured here in 2015, have had their own dramas with the national anthem in Australia.

No technical issue here. Certainly no singing issue. For one of Australia's top gospel singers, this was the moment all performers dread: the mind blank.

Midway through Halstead's rendition of the Maori verse of God Defend New Zealand, there was silence. An eerie, painful silence as the packed house of 6000 shifted in their seats.

Thankfully, Tall Black Paora Winitana rode to the rescue.

"She just put her head down and looked like she was going to cry," Winitana said at the time. "The guys were saying, 'Go out and support her, Paora', so I just walked out and asked if she was all right.

"She just said, 'Hey, I've lost the words'. I said, 'You want me to help you? I'll sing with you, just have another shot'."

They got there in the end, to wild applause.

Then 20, Melbourne-based Halstead said she'd never heard the New Zealand anthem before. "I had gone over the words 100 times in my head, and when I got out there my mind went blank," she said.

Thomas Stowers - All Blacks v Wallabies in Dunedin, 2001

Then 21, Stowers was an up and coming baritone who dreamed of singing at Carisbrook where his grandfather, Tom Katene, played for the All Blacks in a 1955 test against Australia.

Summoned the day before to sing Advance Australia Fair when the original choice missed his flight, Katene appeared to forget the words, hesitating through the first few lines before stopping altogether.

After the Wallabies players and crowd completed the anthem, Katene later explained a technical fault had cut the sound.

"I am really beating myself up about it, but I know it's not my fault, it was just one of those things," he said at the time.

The locals weren't very forgiving, either. "I felt really bad walking through the stadium to get changed. There was lots of jeers and rude gestures."

Hinemoa Mohi - All Blacks v England at Twickenham, London, 1999

While promoting her first album, Oceania, in London, Mohi got the gig via her record company to sing God Defend New Zealand.

Little did she know the storm she would create back in New Zealand when she sang the Maori verse only. She insisted she wasn't trying to make a point, and noted the Maori verse had been sung at a netball test five years earlier without any negative reaction.

Mohi said in 2011: "I felt honoured. I felt so proud and I really didn't anticipate the negative reaction... It was traumatic at the time. I got quite personal attacks. I thought we were more mature as a nation. It's taken a while to work through it.

"It was a statement then, not that I was setting out to make a statement. I was just trying to make the country proud because we all loved the haka and I didn't think the anthem in Maori was so awful. At the time the feedback was quite vicious and if I'd been here in New Zealand I might have been quite worn down by it."

Lizzie Marvelly - New Zealand Maori v British and Irish Lions in Rotorua, 2017

Marvelly, a regular anthem singer at rugby matches, was mortified when her earpiece sound cut out and she faltered over the words, mystifying viewers.

She issued a public apology to the teams and fans via Instagram the following day, labelling it her worst nightmare.

"We wear in-ear monitors so we can hear ourselves when we're singing at games, and last night mine failed during the song I sang before the game," Marvelly explained.

"When mine went, I couldn't hear anything, and I lost my place in the anthem while my brain tried to figure out what was going on. I ripped them out and found my place and carried on but I was utterly devastated to have been thrown."

Her comments prompted an outpouring of support, including a message from All Black Jerome Kaino, who tweeted, "You were Amazing Lizzie!!!"

 - Stuff