Bells for the South Side is a double album of more than two hours on which Roscoe Mitchell contrasts, and for the first time combines, the four trios he was working with. It was recorded live in September 2015 at the Museum of Contemporary Art Chicago, where Mitchell had been invited to premiere new music. The occasion was The Freedom Principle, an exhibition on the art and music set in motion by the AACM on Chicago's South Side, in the association's 50th anniversary year. The programme amounts to a composer's self-portrait, in which Mitchell reflects on his own history while looking ahead.

Each trio pairs Mitchell with two partners, and the nine musicians are heard in changing groups across the set, sometimes one trio alone, sometimes two or three together. Among them are Craig Taborn on piano, organ and electronics and Tyshawn Sorey on trombone, piano and drums. Hugh Ragin plays trumpet and piccolo trumpet, while William Winant covers tubular bells, glockenspiel, marimba, timpani and more. Mitchell plays saxophones from sopranino down to bass, as well as flute, piccolo, bass recorder and percussion. Steve Lake produced the album. It was recorded by David Zuchowski and mixed in May 2016 at Studios La Buissonne with Gérard de Haro.

The opening Spatial Aspects of the Sound sets two pianos against bells, flute and percussion in a slowly unfolding, minimalist texture. Two pieces, the title composition among them, were recorded in the museum's exhibition space. Both draw on the percussion instruments of the Art Ensemble of Chicago displayed there, a panorama of gongs, bells, rattles, sirens and hand drums. Bells for the South Side also carries an extended trumpet feature for Ragin. Elsewhere there is a lyrical bass guitar feature on EP 7849 and a drum solo inside Prelude to the Card Game, Cards for Drums, and The Final Hand. The long final track passes from the atmospheric electronics of Red Moon in the Sky into Odwalla. Mitchell wrote it as the Art Ensemble's theme song.

Critics stressed the range of the writing and the playing. In London Jazz News in 2017 Olie Brice called it "a vital and fascinating recording, full of brilliant compositions and astonishing improvising". Tim Owen of Dalston Sound admitted that "it takes some digesting", then concluded that it is "a superb album". In the Süddeutsche Zeitung, Karl Bruckmaier praised a subtlety and concentration rarely heard. He credited Lake with capturing the music in a transparency that is at moments unsettling.

Released by ECM Records in June 2017 as a double CD, catalogue number ECM 2494/95, with liner notes by Mitchell.