When it was first released as a four-LP package in 1972, this marathon live recording hit #3 on Billboard's Pop album chart and was certified RIAA gold. Following up their 1971 album Chicago III, this historic set features all the early hits and spotlights Chicago at the peak of their initial success. Painstakingly remastered, it now includes a full disc of previously unreleased material showcasing their trademark horns, Robert Lamm's keyboards and vocals, and the guitar virtuosity of the late Terry Kath. The set's packaging makes a nod to the original LP release, with an outer cardboard slipcase, four CDs in individual jackets, a 36-page booklet with original LP artwork, and mini-reproductions of the three huge posters that were part of the original release.