Ichkeria:
Entries have been available for people to listen to, well in advance of the contest , for many years.
Back in 1969, 'Congratulations' was already a number 1 hit in Belgium, Ireland, Denmark, the Netherlands, Norway and Spain when Cliff Richard performed it in Madrid. That's why it was the bookie's favourite to win (and why there are still strong suspicions of vote-rigging that night).
Cheers for the article buenchico: skim read but saved for tomorrow :-)
I remember 1969: Lulu being interviewed by Simon Dee on his Dee Time programme beforehand. I can only have been v small at the time!