As they bashed away at 18 more takes of “Helter Skelter” today, The Beatles were “completely out of their heads,” according to EMI technical engineer Brian Gibson. “Everyone knew what substances they were taking but they were really a law unto themselves in the studio. As long as they didn’t do anything too outrageous things were tolerated.”

This looseness may have had something to do with the fact that authority figure George Martin was not around, having absconded for a vacation and left a young assistant named Chris Thomas in charge. Thomas would go on to become a heavyweight who worked with everyone from David Bowie and Pink Floyd to the Pretenders and the Sex Pistols. But at this point he was a green 21-year-old who was hardly in a position to keep The Beatles in line, if indeed such a thing was even possible.

George Martin didn’t help matters by failing to brief the band before leaving. It seems likely that his taking a break at this point was strictly a matter of self-preservation; The Beatles had been growing increasingly headstrong and contentious, frustrating Martin’s attempts to provide his usual guidance. So he sodded off for a holiday, leaving Thomas a note to “Make yourself available to the Beatles.”

Thomas, quoted in The Complete Beatles Recording Sessions, describes Paul’s reaction this way:

He said, “What are you doing here?” I felt such an idiot, but managed to blurt “Didn’t George tell you?” “No.” “Well, George has suggested I come down and help you out.” Paul’s reply was “Well, if you wanna produce us you can produce us. If you don’t, we might just tell you to **** off!”

And that’s the Cute Beatle speaking! One can only imagine how John reacted. Though if Paul was mean, John was probably nice; that was how they rolled in 1968.

Anyway, it was complete chaos in the studio, says Thomas:

While Paul was doing his vocal, George Harrison had set fire to an ashtray and was running around the studio with it above his head doing an Arthur Brown!

This last is a timely reference to a then-hot act called the Crazy World of Arthur Brown, who back in July had appeared on “Top of the Pops” looking, well, rather like this:

Now that’s entertainment, innit? (Somewhere Vincent Furnier was taking notes.) No wonder The Beatles wanted to channel a little of that vibe as they sought maximum loudness, raunchiness, and ridiculousness for the song that would become their most infamous.

It must have been fun in the studio that day as George played with fire, Paul screamed his head off, John thrashed away at the bass, and everyone yelled at Ringo to hit the drums harder and harder until he got blisters on his fingers.

Feel the urge to kill after that? Maybe just a little? Not to worry, it’s perfectly normal; give it a few minutes and it should pass. Just to be safe, though, make sure you don’t hear “Helter Skelter” again for at least 24 hours.