Chicago is an American rock band formed in 1967 in Chicago, Illinois. Known for their distinctive blend of rock, jazz, and pop, the group became one of the most successful and enduring acts in music history. Originally called Chicago Transit Authority, they shortened their name after their debut album in 1969. With hits like “25 or 6 to 4,” “Saturday in the Park,” and “If You Leave Me Now,” Chicago earned acclaim for their powerful horn section and sophisticated songwriting. Over their decades-long career, they’ve sold over 100 million records worldwide, received multiple Grammy Awards, and were inducted into the Rock and Roll Hall of Fame in 2016.