This instrumental, from the Diver Down album, was recorded on a 1961 Fender Stratocaster (using echo and chorus effects) and was performed by Eddie hammering notes on the fretboard with his left hand while simultaneously rolling the volume knob off and on with his right hand. Eddie did two takes, and the volume knob froze completely at the end of the second take due to the heat generated from rolling it on and off.
John Scanlan (author of Van Halen: Exuberant California, Zen Rock ‘n’ Roll wrote the following for VHND about Eddie’s live performance of “Cathedral”, from his bootleg recorded at Madison Square Gardens, New York City, March 1984:
“A guitar instrumental that on the shorter studio version sounded a bit like a church organ, hence the title. ‘Edward comes into the studio’, Roth said, ‘and he’ll be playing this music and he’ll go, “yeyy, I just made this up.” I walk into the room and go “name it something churchy and it’ll fit.” We work together well that way.’ On this live version the soundscape seems to incorporate more—seagulls squeal and squawk, entire buildings seem to be shifting, floorboards creaking, as Eddie moves it up a notch from the version released on Diver Down. This might be called the Bionic Man version.”
Dave: Edward comes into the studio and he’ll be playing this music and he’ll go, ‘yeyy, I just made this up.’ And he has no idea what it is. But you’ll walk into the room and go, ‘that sounds like Beethoven” or ‘that sounds like a flamingo guitar, let’s call it something Mexican’ or ‘that sounds like Bach, you could play it on the organ’, ‘Bach who?’ says Eddie, ‘don’t worry about it’ says Dave, ‘name It something churchy and it will fit.’ We work together well that way.”
Eddie: “I’ve been doing ‘Cathedral’ for over a year and I wanted to put it on record … it sounds like a Catholic church organ, which is how it got its name. On that cut I use the volume knob a lot. If you turn it up and down too fast, it heats up and freezes. I did two takes of that song, and right at the end of the second take, the volume knob just froze, just stopped.”