The stage is set for a musical European showdown tonight, as the final of the Eurovision Song Contest prepares to get under way.
Last year's competition had to be scrapped completely owing to the emergence of coronavirus across the world, making this the first Eurovision since 2019.
Has COVID-19 had an impact on the contest?
Undoubtedly, with one of the favourites Iceland having to self-isolate after one of act Dadi Freyr's group testing positive for the illness.
It means, despite getting through the semi-final on Thursday, the band's dress rehearsal performance will be shown at the event instead, while the act has to sit in their Dutch hotel room hoping for the best.
Duncan Laurence, the previous winner, was slated to perform on the night, as is Eurovision tradition, but will now also self-isolate instead after testing positive for COVID.
More on Eurovision
Eurovision 2021: Ireland and Australia miss out on spot in final as San Marino reveals star guest performer
Eurovision Song Contest 2021: Bloc voting, stunning vocals and catching a vibe – how do you win the show?
Eurovision Song Contest to allow 3,500 in audience under strict COVID-19 measures
Eurovision 2021: The UK's James Newman says he's 'nailed it' ahead of competition in Rotterdam
Eurovision 2021: Australia to perform in contest from home due to COVID travel restrictions
Eurovision fans allowed inside Rotterdam arena to watch event, Dutch govt says
It also means that Australia (which takes part due to its membership of the European Broadcasting Union) had to perform from home – but missed out a final place regardless.
Acts in the Eurovision bubble have been taking extra precautions over the last two weeks to ensure they can perform on the night, with some missing key rehearsals (which international juries are shown) and media events.
What about the inclusion of Israel?
Israel is no stranger to the contest, and won it in 2018 with Netta's feminist anthem Toy.
However, the conflict between Israel and Gaza has changed the optics on the country's participation in the event this year.
It is politically impossible for Israel to win, coming in around 300-1 to take the trophy, but its inclusion in the contest is not controversial in itself.
The announcement of a ceasefire in the region will be welcome news, but tensions are still high – tensions which could spill over into the arena.
However, organisers have a strict no-politics rule, which has been enforced in the past over the conflict.
Two years ago, when the contest was held in Tel Aviv, the Icelandic act Hatari was fined for holding up Palestinian flags as the camera panned to their green room seats, but it was Madonna who hit the headlines, after two of her dancers displayed Israeli and Palestinian flags on the back of their outfits during her interval performance.
Expect protests outside the arena and some flags in the crowd – but many of the acts will be looking to behave themselves on the night.
Who else is taking part this year?
Twenty-six countries will get three minutes each to encourage Europeans (and Aussies) to pick up the phone and start dialling.
The Netherlands gets an automatic final spot as hosts this year, alongside what are known as the Big Five – The UK, France, Germany, Italy and Spain.
These countries pump the most amount of money into the contest, effectively buying their way into the final.
Joining them from the first semi-final is: Sweden, Ukraine, Malta, Norway, Israel, Russia, Azerbaijan, Belgium, Cyprus and Lithuania.
Going through from the second semi-final is: San Marino, Greece, Moldova, Iceland, Serbia, Albania, Portugal, Bulgaria, Finland and Switzerland.
Bloc voting, stunning vocals and catching a vibe – how do you win the show?
Who is the UK's act?
The man hoping the UK can avoid the dreaded nil points this year is Brit Award winning singer-songwriter James Newman.
He'll perform Embers, a self-penned dance track which he calls "a banger".
Please use Chrome browser for a more accessible video player
Brit hopeful reveals secret to winning Eurovision
Brit hopeful reveals secret to winning Eurovision
Newman told Sky News that he thinks he's "nailed" the song this year and that he's feeling optimistic that he'll do well.
The aim for the UK this year is to appear on the "left hand side of the board", the top 13 if you will, which could very easily happen if he gets it right on the night. Newman goes ninth on the night, and will be backed by two very big trumpets on the stage.
Which are the songs to watch out for and which are the faves?
The bookies are almost always right – but the field of who might win is wider than usual this year.
Unusually, two of the Big Five countries have been carved out as frontrunners, with France's song Voila, sung by Barbara Pravi, in the hunt for the winning spot, as well as Italy's rocky entry Zitti E Buoni, by band Maneskin.
Island nation Malta is also in the running, with previous winner of junior Eurovision, Destiny, performing feminist pop tune Je Me Casse.
Iceland, although now unable to perform live, also has an outside chance, with the fan favourite Dadi Freyr and his track 10 Years – which he wrote about his wife.
His now-defunct entry from last year (which was odds on to win before the event was cancelled) Think About Things went viral after it became hugely popular on apps like TikTok.
Other tracks to watch out for include Lithuania's The Roop singing Discoteque, which comes complete with men in yellow suits doing some hand-choreography – clearly a nod to TikTok dancing crazes.
Meanwhile, San Marino will bring star power to the arena by having actual megastar rapper Flo Rida on stage, reprising his part in Senhit's song Andrenalina – they'll be going last and closing out the competition.
How does voting work?
The public gets a number of votes to use and usually cast their ballots over the phone. Some countries are able to use the app to vote too.
The song which gets the highest amount of votes from a country will be awarded the coveted 12 points by them, second gets 10, third gets eight and then the rest get seven down to one.
The UK's James Newman says he's 'nailed it' ahead of competition in Rotterdam
National juries made up of industry experts will also get to vote for their favourites, and also award up to 12 points to a song.
So one track could get up to 24 points from one country, while it is entirely possible to miss out on points completely – the nil points.
Remember the golden rule though – you cannot vote for your own country.
Who is hosting?
The show is being hosted by Dutch presenter Chantal Janzen, previous contest performer Edsilia Rombley, singer Jan Smit, and YouTube royalty Nikkie de Jager – better known as NikkieTutorials.
When can you watch it?
It all kicks off at 8pm tonight, and it's live on BBC One (which acts as the UK's host broadcaster of the contest).
And of course it will be ably commentated on by Graham Norton, who will bring his own brand of dry wit and humour to proceedings.
Britain's Got Talent judge Amanda Holden will be on hand later in the evening to dish out the points as the UK's spokesperson.