Chicago is an American rock band formed in 1967 in Chicago, Illinois, calling themselves the Chicago Transit Authority in 1968 before shortening the name in 1969. The self-described "rock and roll band with horns" blended elements of classical music, jazz, R&B, and pop music. They began writing songs with politically charged lyrics, and later moved to a softer sound, generating several hit ballads. The group had a steady stream of hits throughout the 1970s and 1980s. In September 2008, Billboard ranked Chicago at number thirteen in a list of the top 100 artists of all time for Hot 100 singles chart success, and ranked them at number fifteen on the same list produced in October 2015. Billboard also ranked Chicago ninth on the list of the 100 greatest artists of all time in terms of Billboard 200 album chart success in October 2015. Chicago is one of the longest-running and most successful rock groups, and one of the world's best-selling groups of all time, having sold more than 100 million records. In 1971, Chicago was the first rock act to sell out Carnegie Hall for a week.
The group now known as Chicago began on February 15, 1967, at a meeting involving saxophonist Walter Parazaider, guitarist Terry Kath, drummer Danny Seraphine, trombonist James Pankow, trumpet player Lee Loughnane, and keyboardist/singer Robert Lamm. Kath, Parazaider, and Seraphine had played together previously in two other groups—Jimmy Ford and the Executives, and the Missing Links. Parazaider, Pankow and Loughnane met as students at DePaul University. Lamm, a student at Roosevelt University, was recruited from his group, Bobby Charles and the Wanderers. The group of six called themselves the Big Thing, and like most other groups playing in Chicago nightclubs, played Top 40 hits. Realizing the need for both a tenor to complement baritones Lamm and Kath, and a bass player because Lamm's use of organ bass pedals did not provide "adequate bass sound", local tenor and bassist Peter Cetera was invited to join the Big Thing in late 1967.
To date, Chicago has sold over 40 million units in the U.S., with 23 gold, 18 platinum, and eight multi-platinum albums. They have had five consecutive number-one albums on the Billboard 200[ and 20 top-ten singles on the Billboard Hot 100. In 1974 the group had seven albums, its entire catalog at the time, on the Billboard 200 simultaneously. The group has received ten Grammy Award nominations, winning one for the song, "If You Leave Me Now." The group's first album, Chicago Transit Authority, released in 1969, was inducted into the Grammy Hall of Fame in 2014. Chicago was inducted into the Rock and Roll Hall of Fame in 2016. In 2017, Peter Cetera, Robert Lamm, and James Pankow were elected to the Songwriters Hall of Fame for their songwriting efforts as members of the music group. Chicago will receive a Grammy Lifetime Achievement Award in 2020.