Substance is a compilation album but it's not a lazy Best of… it's much more important than that. It's a collection of singles, B-sides and sampler tracks, almost all of which don't feature on either of the band's two studio albums. It contains some of their most famous tracks, which are arguably the finest they ever recorded. It's a perfect representation of three years of musical progression, and an essential purchase for fans of Manchester's finest. It's also the perfect starting point for people not familiar with Joy Division's distinctive sound.