February of 1970, not even a year after their debut album Chicago Transit Authority, the band had shortened their name but not their fourteen-legged lineup. As former Bob Dylan sideman and Blood, Sweat and Tears founder Al Kooper told Lamm, Chicago's sound was "�the perfect marriage of brass and rock".

Chicago, born out of their city namesake also known as the "Second City", made the bold Chicago II, a two disc set that would go on to sell a record two million albums and spawn their first Top 5 hit "25 or 6 to 4" and two Top 10 singles "Colour My World" and "Make Me Smile".

Speaking with InTheStudio host Redbeard, keyboardist, singer, songwriter Robert Lamm sheds light on how three lead singers managed to front just one band.

"For most of the time that we were writing songs, we never thought about what key (it's in), is it going to be right for whoever's going to sing it. We would basically write the song and see how far each one of us could go. So part of the idea about sharing lead vocals was necessity." (laughs). - Robert Lamm

Footnote: after over 120,000,000 albums sold, the second biggest selling artist in America (behind only the Beach Boys) is still not in the Rock & Roll Hall of Fame.