%2225 or 6 to 4%22, also written as %22Twenty-Five Or Six To Four%22, is a song written by the American musician Robert Lamm, one of the founding members of the rock/jazz fusion band Chicago. It was recorded for their second album, Chicago in 1970, with Peter Cetera on lead vocals. The song was edited and released as a single in June that year, climbing to number 4 on the U.S. Billboard Hot 100 chart and number seven on the UK Singles Chart. This recording features an electric guitar solo using a wah-wah pedal by Chicago guitarist Terry Kath, and has been included in numerous Chicago compilation albums.An updated version of %2225 or 6 to 4%22 was recorded for the 1986 album Chicago 18 with James Pankow listed as co-writer. With the new band member Jason Scheff on lead vocals, the single reached number 48 on the U.S. chart. This version was also used as the B-side for the band's next single in 1986, %22Will You Still Love Me?%22.The song appears as an on-disc track in the video game Rock Band 3 and has been made available as a download for the game/learning software Rocksmith 2014.