Swedish pop group ABBA, founded in 1972, became famous when they won the Eurovision Song Contest in 1974. It started a decade of almost uninterrupted string of hits and major selling albums. After the group stopped releasing new material in 1982 (they never officially disbanded) there was a relative lull in their popularity – which came to an end in 1992 when "Gold (Greatest Hits)" was released. The compilation has become one of the world's best-selling albums of all time. In 1999, a musical based on ABBA hits called 'Mamma Mia!' opened in London. With various international productions, in 50 countries in all 6 continents, it is one of the most popular musicals of all time. ABBA were inducted into the Rock & Roll Hall of Fame in 2010, in the category of 'Performers'.