Backing Vocals – Lee Loughnane (tracks: C1, C3, D2), Peter Cetera (tracks: C3, D1, D2), Robert Lamm (tracks: C1, C3, D2), Terry Kath (tracks: C1, C3)
Bass – Peter Cetera (tracks: C1, C2, D2, D3), Terry Kath (tracks: C4, D1, D4)
Congas – Guille Garcia (tracks: C2, C4, D2, D4)
Design [Cover] – John Berg, Nick Fasciano
Drums – Danny Seraphine* (tracks: C1 to C3, D2)
Electric Piano [Fender Rhodes] – Robert Lamm (tracks: D2, D4)
Engineer – Jeff Guercio, Wayne Tarnowski
Guitar – Terry Kath (tracks: C1 to C4, D2, D3)
Lead Vocals – Peter Cetera (tracks: C1, D1 to D3)
Lettering – Doris Halle
Mixed By – Phil Ramone
Percussion – Laudir De Oliveira (tracks: C2, C4, D1, D2)
Photography By – Urve Kuusik
Piano – Robert Lamm (tracks: C1, C2, D1)
Producer – James William Guercio
Recorded By [Strings] – Armin Steiner
Supervised By [Quadraphonic Sound Supervision], Engineer [Quadraphonic Remix Engineer] – Wayne Tarnowski
Synthesizer – David J. Wolinski* (tracks: C1, C4, D1)
Tenor Saxophone – Walter Parazaider (tracks: C1, D2 to D4)
Trombone – James Pankow (tracks: C1, C2, D1 to D4)
Trumpet – Lee Loughnane (tracks: C1, C2, D1 to D4)
Original copies have embossed, textured "leather like" covers. They have custom labels and artwork sleeves. Quadraphonic blurb on back cover. Gold labels, which state the name of the band, as well as the name of the album as 'Chicago', like the band's earlier releases. All Quad editions will have a gold label. Checking the jacket alone, the Quadraphonic SQ blurb (in small print, no less), on the back cover is the only way to tell that the album is a quad release.
Matrix / Runout (Record 1 Side 1 Label): QAL 32811
Matrix / Runout (Record 1 Side 2 Label): QBL 32811
Matrix / Runout (Record 2 Side 1 Label): QAL 32812
Matrix / Runout (Record 2 Side 2 Label): QBL 32812