"Like its predecessors it has moments of softness (Tony Iommi's acoustic instrumental Laguna Sunrise, the ballad Changes and the 90 seconds of sonic tomfoolery FX) but whereas the first three albums are all doom classics, Vol 4 red-lined the metal ... Happily, long days "wired" prevented them settling for any of the works-in-progress, instead knuckling down until they had absolutely nailed Vol 4's final, brilliant versions".