Brian Humphries was the sort of engineer I never ignore, because his name turns up exactly where the sound gets deeper, heavier and more cinematic. In 1970 he co-engineered Black Sabbath's "Paranoid", helping trap that blunt, iron-lunged force without polishing away its menace. With Pink Floyd, he entered the frame in 1969 on "Animals" and "Ummagumma", also working on music connected to "Zabriskie Point". He returned in the mid-1970s as front-of-house mixer during 1974, 1975 and 1977, then engineered "Wish You Were Here" in 1975 and "Animals" in 1977. By the late 1970s he was also tied to Britannia Row, right at the point where Floyd's sound became vast, cold and beautifully unsettling.