If you managed to score tickets to ABBA's London gigs at the Royal Albert Hall in 1977, you were in luck. Tickets for the two shows were available only by mail application, and with 3.5 million requests ABBA could have sold out the venue five hundred times.
Today, the Swedish disco foursome of Agnetha Fältskog, Björn Ulvaeus, Benny Andersson and Anni-Frid Lyngstad still remains a global phenomenon.
Their signature song 'Dancing Queen' reached #1 in Ireland and across the globe way back in 1976 and is still considered as the best dance tune ever recorded.
In 1999 the musical stage production based around ABBA's songs Mamma Mia! premiered in London; later adapted for the big screen in 2008, Mamma Mia!, became Britains highest-grossing movie.
Since their break-up in 1982, ABBA has refused to reunite despite countless offers including a billion-dollar deal in 2000.
"Money is not a factor, and we would like people to remember us as we were - young, exuberant, full of energy and ambition," said producer and band member Björn Ulvaeus.