By Jose Miguel Galvan Deniz
BBC education reporter
Greenjolly have been told to rewrite the lyrics to their Eurovision entry
This year's Eurovision Song Contest hosts Ukraine are rewriting their entry, the anthem of the country's "orange revolution", after organisers said it was too political.
The row over the lyrics of the Ukrainian entry is yet another episode in the competition's attempt to remain immune to political events throughout its 50-year history.
The contest was born in 1955, the result of a well-intended wish for Europe to unite, at least, in song.
As early as 1961 the first representatives of fascist Spain and communist Yugoslavia shared the stage, in the best sporting fashion.
And four years later the annual event was being broadcast across the former Soviet Union and the Eastern bloc countries, although it was not until after the fall of the Berlin Wall that they were allowed to join in the competition.
In the late 60s the songs from the dictatorial Iberian regimes started to feature metaphors for freedom, disguised as love songs in order for them to get past the official censors.
Massiel beat Cliff Richard at the contest in 1968
When Portugal was still the colonial power in Angola, local singer Eduardo Nascimento sang The wind's changed.
More notoriously, 1968 Spanish entry La, la, la was allegedly born as a protest song.
The male artist originally appointed to perform it insisted on singing in Catalan during his live performance, at a time when the language was forbidden in public life within Spain.
A replacement was hastily found, the song was re-arranged from the original acoustic version, and it went on to beat Cliff Richard's UK entry.
In a twist of fate, this victory in Europe and over Britain was maximised by Franco's regime for its own propaganda purposes.
However, winds of change were blowing from within the regime's own apparatus.
In subsequent years Spain's national entries featured lyrics exalting the virtues of "a new world at the end of the road" or "a brighter dawn in a place beyond the sea".
Israel's Ping Pong attracted controversy by waving Syrian flags in 2000
For the year that Abba won, 1974, Portugal sent a song which would become part of the country's history three weeks after the contest.
The left-leaning military plotted a coup to overthrow the dictatorial regime. The coded signal for the onset of the uprising would be broadcast over Catholic Radio Renascenca.
It was agreed by the generals that the signal would be that year's Eurovision entry. And so, as Paulo de Carvalho's After goodbye played on the radio in the evening of 25 April 1974, the Carnation Revolution started.
Israel had joined Eurovision a year earlier.
In the aftermath of the Munich Olympics massacre, their performer had to sing in a bullet-proof vest, and all security personnel in the small host country, Luxembourg, had their leave cancelled.
The Spanish entrant in 1978, from the Canary Islands, was also under heavy security protection.
He had received death threats from a separatist group advocating independence from Spain for the islands.
Also in the 70s Greece and Turkey joined in successive years, each withdrawing in protest against the other over a row over the division of Cyprus. Turkish TV still showed the event but opted out during the Greek performance.
By comparison, the 80s were relatively quieter.
At the beginning of Ronald Reagan's US presidency, there was a song in French by the title of Maybe it isn't America (because America isn't the be-all), and at the height of the Falklands war in 1982, the Spanish entry in the event, hosted in the UK that year, was a tango.
The momentous fall of the Berlin Wall was clearly reflected in the subsequent 1990 contest.
Germany sang Free to Live and Austria performed No More Walls - joined by Norway's Brandenburg Gate, which came last in the voting.
In contrast, Italy came first with Together: 1992 - the first time in 35 years that victory went to an anthem which actually and literally exalted European unity, looking ahead to the Maastricht treaty.
In 1992, as the Balkan War unravelled, a dismembering Yugoslavia still took its place on stage.
The following year they were shunned from the competition, at the same time as the doors opened to Eastern European countries.
However, these had to go through a pre-selection as only three places were made available for them, eventually won by the new Balkan republics of Croatia and Bosnia-Herzegovina.
A year later, the Bosnian conductor had to be smuggled out during the siege of Sarajevo, and as the delegation took to the stage the crowd received them with rapturous applause.
Indeed former Eastern bloc countries saw the contest as a way of gaining visibility, albeit briefly, in the international arena.
Successive victories allowed Estonia and Latvia to showcase themselves as hosts in 2002 and 2003, the year when the Poles, looking forward to their accession to the EU, entered the song No borders.
Their singer sang it in both Polish and German, with his hair dyed red and dressed in white, the colours of the national flag.
But a less cryptic flag incident in 2000 remains the most controversial political gesture seen on stage to this day.
The Israeli entrants, the innocuously named Ping Pong, finished their song Be Happy by unfurling Syrian flags and calling for peace, to the shock of many in their home country.