New to Eurovision? Here's a quick guide to the biggest music competition in the world - a guilty pleasure for some, a reason to get up at dawn for others. We look at who's voting, why Australia is involved and some of the rules Eurovision performers must abide by.
History: Eurovision started in 1956, making it the longest-running annual international TV song competition.
How many countries take part? Forty-two. This year sees the return of Ukraine, Croatia and Bosnia and Herzegovina.
Why is Australia taking part in Eurovision? The country got a "surprise" entry last year to celebrate the event's 60th anniversary, apparently a thank you for its support over the years. Despite Australia's inclusion being called "stupid" by host Graham Norton, Oz is back again this year.
Who will represent Australia? Korean-born, Brisbane-based Dami Im, who won The X Factor three years ago and has just released an album of Carpenters covers. Her X Factor performances, guided by mentor Dannii Minogue, mixed camp theatrics with powerhouse vocals - the cornerstone of Eurovision. She follows Guy Sebastian, who came a very respectful fifth in last year's competition.
This year's location: Sweden, because last year's winner Mans Zelmerlow was Swedish. That's how it moves around Europe. If you win, your country hosts it the next year.
What if Australia wins? Yes, that could be tricky. The theory is they would just pick a country in Europe to play host.
This year's venue: The Ericsson Globe in Stockholm, which can hold up to 16,000 fans and accommodate copious amounts of pyrotechnics, glitter, hairspray and wind machines.
Viewers: Up to 180 million globally.
Hosts: Last year's winner Mans Zelmerlow and Swedish TV star Petra Mede.
Special guests: Zelmerlow will perform last year's winning song Heroes and Justin Timberlake will perform Can't Stop the Feeling at the final - did we mention it gets 180 million viewers? JT could be the artist who benefits most from the event.
Who votes: It has changed this year, for the first time since 1975. Votes are now split equally between each country's professional jury and TV voters. These votes decide which countries are eliminated before the finals start. Countries cannot vote for themselves.
The rules: All vocals must be performed live. No promoting brands (The Facebook Song was changed to The Social Network Song in 2012). No overly political statements, gestures or swearing on stage or in any Eurovision-related area including media centre and backstage. Songs cannot be longer than three minutes. A maximum of six people on stage. No live animals. Contestants must be over 16. You can sing in any language. Songs performed must not have been commercially released before September 2015 in any form.
Eurovision success stories: Some acts got their start on Eurovision, others were established and used the event as a career move - Abba, Sandie Shaw, Bucks Fizz, Celine Dion, Tatu, Gina G, Lulu, Conchita, Lordi, Brotherhood of Man, Katrina and the Waves, Bonnie Tyler, Englebert Humperdinck and Olivia Newton-John.
Classic Eurovision song titles: Boom Bang a Lang, Diggi-Loo, Diggi-Ley, Ding-a-Dong, Ooh Aah ... Just a Little Bit.
Most successful countries: Ireland has won seven times, Sweden six and Luxembourg, France, and the United Kingdom five times.
Least successful countries: Norway has come last 11 times, but has also won three times.
When: Sunday 7am (live) and 7.30pm