Singer, songwriter, multi-instrumentalist, and composer Sir James Paul McCartney is arguably the most successful musician in modern times. With John Lennon, George Harrison, and Ringo Starr, he gained worldwide fame as a member of the Beatles, and his collaboration with Lennon is one of the most celebrated songwriting partnerships of the 20th century. After the group's break-up, he pursued a solo career, later forming the band Wings with his first wife, Linda, and singer-songwriter Denny Laine. Guinness World Records described McCartney as the "most successful composer and recording artist of all time," with 60 gold discs and sales of over 100 million albums and 100 million singles, and as the "most successful songwriter" in UK chart history. More than 2,200 artists have covered "Yesterday" - more than any other song in history. Wings' 1977 release, "Mull of Kintyre," is one of the all-time best-selling singles in the UK. Inducted into the Rock and Roll Hall of Fame as a solo artist in March 1999, McCartney has written, or co-written 32 songs that have reached number one on the Billboard Hot 100, and as of 2012, he has sold over 15.5 million RIAA-certified units in the United States. Paul McCartney continues to tour the world.