Chicago…If you like your rock 'n' roll mixed with an exciting blast of horns there is no better listen than the music group Chicago.  Formed in the city of Chicago in 1967 the band produced a steady stream of hits throughout the 1970s and 1980s.  In fact, Chicago has sold over 100,00,000 albums and according to Billboard Magazine Chicago is the most successful American group ever.  Using performance and interview clips, we'll trace the arc of their career from their early rock 'n' roll successes like "25 or 6 to 4" and "Saturday In The Park" to their softer hits like "If You Leave Me Now" and "Hard To Say I'm Sorry."