ABBA's 'Dancing Queen' topped charts 40 years ago

ABBA
Swedish pop group ABBA, pictured April 7, 1974.
Evening Standard | Getty Images 1974

"Dancing Queen" by ABBA hit No. 1 on the U.S. pop chart 40 years ago Monday.

Surprisingly, it is the only ABBA song to ever top the charts in the United States. In 2012 a deejay for the BBC reported on an event at Windsor Castle where Queen Elizabeth was seen on the dance floor during this song.

The monarch, who was 82 at the time, told people around her "I always try to dance when this song comes on because I am the queen and I like to dance."