ABBA
All four ABBA members had local music careers before ABBA even formed. Frida and Agnetha were both solo singers. Benny and Bjorn both had their own individual bands. In 1966, Benny and Bjorn both met and decided to write songs together. In 1969, Bjorn met Agnetha and Benny met Frida. All four friends met together and decided to work together to record songs.