Before they won the Eurovision Song Contest in April 1974, few people outside Scandinavia had heard of ABBA - indeed, before Waterloo, the quartet were credited as 'Bj?rn Benny & Agnetha Frida' on the few singles they released and on their debut album, as the name ABBA hadn't been coined.Bj?rn, Benny, Agnetha and Frida were all successful musicians in their own right, before they formed a group together, and they continued to enjoy success after ABBA...