Chicago "If You Leave Me Now (Single & Video)"

"If You Leave Me Now" is a song by the American rock group Chicago, from their album Chicago X. It was written and sung by bass player Peter Cetera and released as a single on July 30, 1976. It is also the title of a Chicago compilation album released by Columbia Records (Columbia 38590) in 1983.

The single topped the Billboard Hot 100 on October 23, 1976, and stayed there for two weeks, making it the first number one hit for the group as well as hitting number one on the Easy Listening charts. "If You Leave Me Now" was also Chicago's biggest hit internationally, topping the charts in other countries such as the UK, Australia, Ireland, Canada, and Netherlands. In the UK it maintained the number one position for three weeks. It was one of five "non-disco" songs to make it to number one in the US in a nine-month period of 1976. According to writer Zachary Houle of PopMatters, "The song was so pervasive on radio upon its release that, reportedly, those tuning in within New York could hear the song playing on four different stations, each with varying formats, simultaneously."

The song won Grammy Awards for Best Arrangement Accompanying Vocalist(s) (strings) for arranger Jimmie Haskell and producer James William Guercio and Best Pop Vocal Performance by a Duo, Group or Chorus, the first Grammy Award won by the group. It also received a Grammy nomination for Record of the Year. In addition, by August 1978 it had sold 1.4 million copies in the United States alone. It has been certified gold and platinum by the RIAA. In an article from June 2020, The Guardian listed "If You Leave Me Now" as number 73 on its list of "The Greatest UK No 1s: 100–1", noting, "It’s impossibly lush and beautifully written, but its sadness is pervasive and affecting."

In 2010 Chicago teamed with the American Cancer Society and offered the opportunity to bid on the chance to sing their hit, "If You Leave Me Now" with them on stage live at their concerts, with proceeds going to the American Cancer Society to fight breast cancer. The fund raising effort has continued in succeeding years.

Peter Cetera originally wrote "If You Leave Me Now" at the same time as Chicago VII's "Wishing You Were Here", and composed it on a guitar. According to information on the sheet music for the song at MusicNotes, "If You Leave Me Now" is written in the key of B major, and Cetera's vocal range varies between F sharp 4 (F♯4) and D sharp 6 (D♯6).

Cash Box said that it's "an excellent ballad," with "lushly colored" instrumentation and "carefully constructed" vocals.