There’ve been a lot of weird pop collaborations over the years, but this team effort between jazz bassist/electronic engineer David Vorhaus and notable BBC Radiophonic Workshop veterans Delia Derbyshire and Brian Hodgson — best known for their groundbreaking electronics work on Doctor Who — has to rank up there. Technically a pop record but filled with uncanny effects, weird moans, and surreal poetry on the first half and absolutely jaw-dropping ambient compositions on the second, it all culminates in an improvised piece called “Black Mass: An Electric Storm in Hell,” which sends 21 gigawatts of electric current through the River Styx. Unprecedented at the time, shocking even now.