By Michael Osborn
Entertainment reporter, BBC News
Winners from each of the six decades of the Eurovision Song Contest
The Eurovision Song Contest began in 1956 as a modest event involving just seven countries.
It has gone on to run for more than 50 years, and has expanded to encompass up to 43 participants.
Loved and derided in equal measure, we help you pick your way through this musical institution and glance at what makes it unique.
The language has only been heard once at Eurovision, thanks to a one-off entry by Morocco in 1980. But it's making a comeback in 2009 with Israel's entrants Noa and Mira Awad (pictured), whose song also features Hebrew and English.
Language has always been a big issue at the contest, but Belgium take the prize for fielding songs in 2003 and 2008 that consisted of lyrics in made-up tongues.
Sandie Shaw's trademark shoeless feet made their way to the Eurovision stage in Vienna, 1967, where she claimed the UK's first of five victories to date.
In 1983, Spanish singer Remedios Amaya also decided to cast aside her slingbacks, but the ploy was less fruitful. The Flamenco songstress's mournful lament finished last with no points.
CAN WE HAVE YOUR VOTES, PLEASE
Watching the performances - some might say - is just a tedious preamble to the legendary Eurovision voting and scoreboard, which gives many British viewers their annual exposure to the French language.
The jamboree of calling up each country is fraught with potential pitfalls, from the vote announcer taking too long to gush over what a wonderful show it was, to muddling up their scores in the heat of the moment.
Since announcers began appearing in vision, former entrants have often returned to bask in the glory, including the UK's Cheryl Baker from 1981 winners Bucks Fizz (pictured in 2005).
The modern era of televoting and free movement around Europe has led to some interesting quirks in Eurovision voting from migrants supporting their home countries. A strong Romanian contingent in Spain has led to the country awarding douze points to the Balkan nation, while Ireland's Baltic communities have pushed the country into giving top marks to Latvia and Lithuania in recent contests. A new voting system in 2009 (see juries) may dampen the influence of diasporas.
The collapse of communism transformed Eurovision from a cosy western European club into a contest taking in the former Soviet Union, Croatia, Slovenia, Poland and Albania. Georgia, Armenia and Azerbaijan (pictured) have recently joined the fray. Some fans admit to having teary-eyed nostalgia for the Eurovision of old.
At the end of the 1969 contest, the UK, France, Netherlands and Spain were level on points, creating confusion as the organisers had no idea how to fix it. The four-way tie prompted five countries to boycott the 1970 competition. They were better prepared in 1991 when Sweden and France finished level at the top - a countback system saw the Swedes win the day.
Some of Greece's best-known female singers have performed on the Eurovision stage - but not always for their country of birth. Musical legend Nana Mouskouri represented Luxembourg in 1963. Vicky Leandros (pictured) sang for the Grand Duchy in 1967, and took the country to victory with rousing ballad Apres Toi in 1972. It was left to Helena Paparizou to score Greece's only win to date in 2005. Ironically, she was born and brought up in Sweden.
HOSTS AND HOSTESSES
After a bevy of glamorous (if stern) female solo hosts, the Eurovision has been presented by a succession of male-female double acts, with varying degrees of success.
The UK plumped for Terry Wogan and Ulrika Jonsson in 1998, while Irish star Ronan Keating and previous competitors Zeljko Joksimovic, Sakis Rouvas and Renars Kaupers have all tackled the presenting gig.
ITALY (WE MISS YOU)
Italy was one of the original Eurovision nations who have managed two victories to date. They last appeared in 1997, citing financial issues and the existence of their own San Remo Festival for staying away. But last year, their tiny neighbour San Marino (entrants Miodio, pictured) graced the contest, stoking calls for an Italian renaissance. Five-time winners Luxembourg are also sorely-missed absentees from the original shake-up in 1956. Come back, why don't you?!
Until 1998, jury panels made up of members of the public were used to decide the winner of the contest. The advent of telephone voting led to increasingly predictable scoring, prompting organisers to try a mix of public and jury voting in 2009. While the public sat on panels back in the day, this time music industry experts will deliver their verdicts. Their decisions could be very different to those of viewers.
The queen of Eurovision hostesses merits a separate entry for having chalked up four contests in her time during the 1960s and 1974, when Abba scored their famous win in Brighton. Renowned for her crisp style and command of languages, Katie, now 82, had to host the show wearing no underwear as it could be seen under the studio lights. Her most recent appearance was on a Eurovision Weakest Link special in 2004.
The Irish crooner holds a unique place in Eurovision history for being the only performer to sing two winning songs, in 1980 and 1987, which were UK hits. In 1992 it was third time lucky as a songwriter, with Why Me performed by Linda Martin - the first of Ireland's incredible run of four wins during the 1990s.
A mature Moldovan lady who leapt off her rocking chair and banged a drum was the surprise hit of the 2005 contest. But she was outdone last year by Croatian performer 75 Cent - the clue to his age is in the name.
Youthful performers have also made their mark, with Belgium's only winner, Sandra Kim, lifting the trophy at the tender age of 13. Singers now have to be at least 16, while the Junior Eurovision spin-off kicked off in 2003.
A glaring absence of points at the end of the contest has to be the biggest embarrassment Eurovision has to offer. Hapless UK act Jemini (pictured) heaped shame on their country in 2003, while the most recent country to finish with a big fat zero was Switzerland in 2004 - and that was in the semi-final. Norway take the spoils with four nul points, but on the flip side, the Nordic country won twice - in 1985 and again a decade later.
A big live event usually encounters hiccups, and Eurovision is no exception. In 1990, Spanish act Azucar Moreno were first on stage in Zagreb and their backing track jammed. The pair abandoned their performance and had to start all over again. As the delay dragged on, UK commentator Terry Wogan quipped: "This could be a long evening, ladies and gentlemen," and offered to hum the song's opening refrain.
They are officially banned at Eurovision, but a seemingly innocuous Portuguese song in 1974 was the trigger for a revolution back home. Organisers have weeded out any recent controversy, telling Ukraine to tone down the lyrics of their 2005 Orange Revolution anthem. Georgia withdrew in 2009 after their anti-Russian jibe fell foul of the censors.
Winning your national final is one thing, but now there are further hurdles to jump. To stop the contest dragging on for days, a semi-final was introduced in 2004, and was split into two last year. Andorra and Estonia have failed to make the grand final, while old timers Belgium and the Netherlands have fared badly since Eurovision became a beast of vast proportions.
"Big Four" the UK, France, Germany and Spain sail into the final thanks to the money they throw at the event.
It's an experimental musical style for Eurovision, but the UK has tried it twice with 1995's Love City Groove and Daz Sampson in 2006. Neither of them lit up the scoreboard. The most successful rap entry came from Bosnia in 1999 and wound up in 7th place. In 2009, Finnish act Waldo's People have an uptempo pop song with rap at its core - maybe it's time for a breakthrough.
Some acts just can't get enough. Eurovision's first winner from 1956 sang two numbers in that contest, and Swiss star Lys Assia returned in 1957 and 1958. In the modern era, Maltese chanteuse Chiara notches up her third appearance in 2009. But experience doesn't always pay - Sweden's 1999 winner Charlotte Perrelli returned in 2008 and limped home in 18th place.
The UK's Michael Ball, on the other hand, said he'd rather "stick needles in my eyes" than return to Eurovision after finishing second in 1992.
Israel's narrow victory in the 1998 contest held in Birmingham was one of the most memorable, with singer Dana International making headlines for her status as a post-operative transsexual. The huge support she built up and the early days of televoting helped her win the title - but some fans would argue that her hi-octane song Diva was not the best on the night.
USE OF PROPS
All manner of seemingly random objects have been brought on stage over the years in an effort to make performances more memorable, including a barrel organ and puppets (Netherlands, 1974). Bigger stages have meant more props in recent years, including a washing line, golf buggy and a bus stop sign (Hungary, 2007). Live additions such as animals are not allowed in Eurovision performances, strangely enough.
Or countries who are still desperate to pop their Eurovision-winning cherry. So many new countries have joined the show in recent years that the list is long - but the prize goes to Portugal, who are still waiting after more than 40 attempts. They came second in 2008, albeit in one of the semi-finals. Stalwarts Malta and Cyprus are still holding out for a victory.
In 1985, Sweden's Eurovision host Lil Lindfors lost her skirt as she came on stage - but the incident was a highly stage-managed piece of entertainment, as was the legendary skirt-ripping moment by Bucks Fizz in 1981. It led to costume changes during songs becoming the norm, with Belarus's Angelica Agurbash revealing two fresh outfits in 2005.
That same year, UK hopeful Javine suffered genuine blushes when she accidentally exposed her breast during the country's live national final.
XENA WARRIOR PRINCESS
The star and winner of the 2004 contest in Istanbul was a fresh-faced, lively Ukrainian called Ruslana Lyzhicko, who wowed the contest with a thumping, energetic dance routine and a fetching fur and leather ensemble with more than a passing nod to cult TV show Xena Warrior Princess.
Free-wheeling Yugoslavia was the only socialist country to take part in the Eurovision Song Contest from 1961. They scored their only victory in 1989.
From the early 1990s the nation's dissolution was mirrored on the musical stage as new states including Croatia and Slovenia entered the fray. The most recent addition was Montenegro. The former Yugoslavia may have become a formidable voting bloc, but only Serbia (2007) has secured a win.
The popular Serbian singer-songwriter has rapidly turned into a Eurovision fixture in recent years. He sang Serbia and Montenegro's debut entry Lane Moje in 2004, finishing in second place. Two years later, he penned Bosnia's effort Lejla, which came third. Not content with co-hosting the contest when it came to Serbia in 2008, he also wrote the host country's song. Phew.