Background: Chicago is an American rock band formed in 1967 in Chicago, Illinois as The Chicago Transit Authority before shortening the name in 1970. The self-described "rock and roll band with horns" began as a politically charged, sometimes experimental, rock band and later moved to a predominantly softer sound, generating several hit ballads. The group had a steady stream of hits throughout the 1970s and 1980s. Since at least 2008, Billboard has shown Chicago to be the "greatest of all time" American band in singles chart success, and since 2015, the "greatest of all time" American band in album chart success as well.
Context: Concurrently with Chicago's existing career, lead vocalist Peter Cetera had begun a solo career. He proposed an arrangement with the band where they would take hiatuses after tours to let him focus on solo work (mirroring that of Phil Collins and Genesis), but the band declined. Cetera ultimately left Chicago in the summer of 1985. He soon topped the charts with "Glory of Love" (the theme song of the film The Karate Kid Part II), and with "The Next Time I Fall" (a duet with Amy Grant). Two more songs reached the Top Ten: a 1988 solo hit called "One Good Woman" (No. 4 U.S.), and a 1989 duet with Cher called "After All" (No. 6 U.S.). In 1992, Cetera released his fourth studio album, World Falling Down, which earned him three hits on the Adult Contemporary charts, including the single "Restless Heart". Cetera's former position was filled by bassist and singer-songwriter Jason Scheff, son of Elvis Presley's bassist Jerry Scheff. Guitarist Chris Pinnick also left the group prior to the recording of the band's next album.  For the final Foster-produced album, Chicago 18, the band filled Pinnick's spot with several session guitarists, none of whom became band members. The album was released on September 29, 1986, and included the No. 3 single "Will You Still Love Me?", and Top 20 Pop song "If She Would Have Been Faithful...", in addition to an updated version of "25 or 6 to 4" with a video that got airplay on MTV. Soon after the album was recorded, the band hired guitarist Dawayne Bailey, formerly of Bob Seger's Silver Bullet Band. Bailey and Scheff had previously played in bands together, so Scheff introduced Bailey to the band in time for the Chicago 18 tour.  For the 1988 release, Chicago 19, the band had replaced producer Foster with co-producers Ron Nevison, who had recently produced two albums for Heart, and Chas Sanford, who had worked with Rod Stewart and Stevie Nicks. They topped the charts again with the Diane Warren-composed single "Look Away". It was the third and last Chicago single to reach No. 1 on the Hot 100 chart. The song ultimately was named as the "Billboard Hot 100 No. 1 Song of the Year" for 1989. The album also yielded two more Top 10 hits, "I Don't Wanna Live Without Your Love" and "You're Not Alone", both with Champlin singing solo lead for the first time, and the Scheff-sung No. 55 single, "We Can Last Forever," in addition to including the original version of a Top 5 single titled "What Kind Of Man Would I Be?". The latter, also sung by Scheff, was remixed for inclusion on the band's forthcoming greatest hits record (and 20th album), Greatest Hits 1982-1989, and it was this version that became a hit.
Question: What led to Cetera's departure?
Answer: Concurrently with Chicago's existing career, lead vocalist Peter Cetera had begun a solo career.

Background: Kimberley Ann "Kim" Deal (born June 10, 1961) is an American singer, songwriter and musician, best known as the former bassist and backing vocalist of the alternative rock band Pixies, and the lead vocalist and rhythm guitarist for The Breeders. Deal joined Pixies in January 1986 as the band's bassist, adopting the stage name Mrs. John Murphy for the albums Come on Pilgrim and Surfer Rosa. Following Doolittle and The Pixies' hiatus, she formed The Breeders with Tanya Donelly, Josephine Wiggs and later introduced her identical twin sister Kelley Deal. The Pixies broke up in early 1993, and Deal returned her focus to The Breeders, who released the platinum-selling album Last Splash in 1993.
Context: Deal became the bassist and backing vocalist for Pixies in January 1986, after answering an advertisement in the Boston Phoenix that said, ""Band seeks bassist into Husker Du and Peter, Paul and Mary. Please - no chops." Deal was the only person to call them, even though her main instrument was guitar. She borrowed her sister Kelley's bass guitar to use in the band. To complete the lineup, she suggested they hire David Lovering as drummer, a friend of her husband, whom she met at her wedding reception. For the release of the band's first recording Come on Pilgrim (1987), Deal used the nom de disque "Mrs. John Murphy" in the liner notes. She chose the name as an ironic feminist joke, after conversing with a lady who wished to be called only by her husband's name as a form of respect.  For Surfer Rosa (1988), Deal sang lead vocals on the album's only single, "Gigantic" ( sample ), which she co-wrote with Black Francis. Doolittle followed a year later, with Deal contributing the song "Silver" and appearing on slide guitar. By this time, however, tensions began to develop between her and Francis, with bickering and standoffs between the two marring the album's recording sessions. This led to increased stress between the band members. Murphy commented that during the sessions, it "went from just all fun to work". Exhaustion, from releasing three records in two years and constant touring, contributed to the friction, particularly between Francis and Deal.  The tension and exhaustion culminated at the end of the US "Fuck or Fight" tour, where they were too tired to attend the end-of-tour party. The band soon announced a hiatus.
Question: Did they end up breaking up?
Answer:
The band soon announced a hiatus.