April 9, 1977 –
ABBA had their only no. #1 US hit on the Billboard Charts – Dancing Queen, on this date.
ABBA recorded this about a year before it was released. It was written and recorded around the same time as Fernando, which was chosen as the single. They knew Dancing Queen would also be a hit, so they held it until the album was released before issuing it as a single.
The Haus of Dcaligari 