Eight of the songs on Concrete were re-recorded in 1992 and released on Soul of a New Machine: "Big God/Raped Souls", "Arise Above Oppression", "Crisis", "Escape Confusion", "Dragged Down by the Weight of Existence" (re-recorded as "W.O.E"), "Desecrate", "Suffer Age", and "Self Immolation".
"Piss Christ" is not the same song as "Pisschrist", which appears on Demanufacture.