Sweden's Melfest: Why a national Eurovision show won global fans

"It's something that unites Swedes," explains 2015 Eurovision winner Mans Zelmerlow.

To represent Sweden at the song contest he first had to win Melodifestivalen - a six-week long competition.

Celebrating its 60th year, Melodifestivalen - or Melfest to fans - has been Sweden's most-watched TV show since 2000.

It's developed a global interest, with fans flying to Stockholm from across Europe for Saturday's final.

"This is my second time going to Melfest," explains 20-year-old Luke Hardwick.

"I love all the tension, it's like a mini-Eurovision before the main event and it's great to meet other fans from around the world counting down to May."

It took time to convince his friends to try Melfest, but now they're avid fans too and he's travelled to the Swedish capital this year with four others.

Luke watches other national selection shows but says "nothing beats" the Swedish version.

"Being on Melodifestivalen had been a childhood dream of mine," Zelmerlow tells the BBC.

"Eurovision broke Abba worldwide and we have such pride in them and we want that to repeat again."

The winner is able "to get as close to the Olympics" as a musician can, he says - with 41 countries taking part in this year's Eurovision Song Contest in the Netherlands.

It's estimated more than 70% of Sweden's 10.3m population watched this year's heats - more than a million more than even Eurovision gets in the Scandinavian country.

Support for Melfest has grown from outside of Europe, and it was described last week as "the techno version of the primaries" by James Corden during a segment on his US late-night chat show - uploaded to 23 million subscribers on YouTube.

One of this year's Melfest finalists, 2010 winner Anna Bergendahl, believes platforms like Twitter and YouTube have played a huge part in increasing the show's fanbase outside Sweden.

"Back in 2010 social media was not a thing," the 28-year-old tells the BBC. "Coming back, all these fans from around the world started emerging who I didn't know existed."

Bergendahl has "some serious unfinished business" after she failed to qualify from the Eurovision semi-finals in 2010, making it the only time Sweden has not reached the final in the contest.

"It would be such a full circle if I was to represent Sweden 10 years later," she explains. "My biggest goal right now is to finally redeem myself."

This year's favourite to win, Dotter, entered Melfest "to show the world my song" and she believes a win would be huge for her career.

"I wanted to show this in the biggest spotlight possible," says the 32-year-old singer. "I didn't want to just release it on Spotify, because then I would only get 200,000 streams."

Twenty-two-year-old teacher Eliza Moore, who watches the show on a live stream in North-East England, believes Melodifestivalen is one of the reasons Sweden consistently does well at Eurovision.

"You become really enthusiastic for them because you go through a journey with them watching Melfest," she tells the BBC.

Melfest has discovered six Eurovision winners - two in the past 10 years. Its most famous act was undoubtedly Bjorn, Anni-Frid, Agnetha and Benny.

1974: Abba - Waterloo

1984: Herreys - Diggi-Loo Diggi-Ley

1991: Carola - Fangad av en stormvind (Captured by a love storm)

1999: Charlotte Nilsson - Take Me to Your Heaven

2012: Loreen - Euphoria

2015: Mans Zelmerlow - Heroes

Another of Melfest's winners was Malena Ernman, whose song The Voice came 21st in Eurovision in 2009. She is perhaps better known nowadays as the mother of climate change activist Greta Thunberg.

Sweden has become a huge player in modern pop music, with producers such as Max Martin and RedOne creating global hits for acts like Taylor Swift, Lady Gaga and Ariana Grande.

"We're proud of our music scene here," Dotter, who's performing Bulletproof, explains. "I just feel glad I get this chance to be part of it."

The final of Melodifestivalen begins at 19:00 GMT on Saturday. It can be streamed internationally here.