***ABBA-is a Swedish pop music group formed in Stockholm in 1972, consisting of Anni-Frid "Frida" Lyngstad, Björn Ulvaeus, Benny Andersson and Agnetha Fältskog. They became one of the most commercially successful acts in the history of popular music, topping the charts worldwide from 1972 to 1983. As their popularity grew, they were sought after to tour Europe, Australia, and North America, drawing crowds of fans. Due in part to the fact that touring became a contentious issue, being particularly cumbersome for Fältskog, producer Stig Anderson became one of the very first to make promotional film clips which were the forerunner of today's music video to increase exposure to the group's music in addition to releasing studio albums to widespread commercial success. Throughout the band's existence, Fältskog and Ulvaeus were a married couple, as were Lyngstad and Andersson - although both couples later divorced. At the height of their popularity, both relationships began suffering strain that led ultimately to the collapse of first the Ulvaeus-Fältskog marriage (in 1979) and then of the Andersson-Lyngstad marriage in 1981. In the late 1970s and early 1980s these relationship changes began manifesting in the group's music, as they produced more introspective lyrics with different compositions. ABBA remains a fixture of radio play lists and is one of the world's best-selling bands, having sold over 375 million records worldwide, making them the fourth best-selling popular music artists in the history of recorded music. They still sell two to three million records a year. ABBA was the first pop group from a non-English-speaking country to enjoy consistent success in the charts of English-speaking countries, including the UK, the US, Canada, Ireland, South Africa, Australia and New Zealand. As well as reaching the top of the charts in different countries like Mexico, Argentina, Brazil, Colombia and Peru among others, the band also released a compilation of their hit songs translated into Spanish. After ABBA split, Andersson and Ulvaeus achieved success writing music for the stage while Lyngstad and Fältskog pursued individual solo careers with varying success. ABBA's music remained steadily popular until several films, notably Muriel's Wedding and The Adventures of Priscilla, Queen of the Desert, revived interest in the group, spawning several tribute bands. In 1999, ABBA's music was adapted into the successful musical Mamma Mia! that toured worldwide and had a movie version released in 2008, becoming the highest grossing film in the UK at the time. The group was inducted into The Rock and Roll Hall of Fame on 15 March 2010.***