A dilruba.

John Lennon was probably not the only person to take LSD at Abbey Road this week — the original, Syd Barrett–led lineup of Pink Floyd was around working on their debut album, The Piper at the Gates of Dawn. Floyd producer Norman Smith, a former Beatles engineer, introduced the two bands, but there doesn’t appear to have been much interaction between them. “They were God-like figures to us,” says Floyd drummer Nick Mason. “They all seemed extremely nice, but they were in a strata so far beyond us that they were out of our league.”

The main item on the agenda for today’s session was to overdub more dilrubas onto the existing tracks for “Within You Without You.” How many dilrubas does it take to fill up a Beatles song? (I’ve been sitting here for the last 15 minutes trying to think of a good joke involving the word “dilruba,” and that’s the best I could come up with. A little help? Anybody?)

Later in the night, the band gathered to listen to a playback of all the Sgt. Pepper songs recorded so far. I like to picture them all in their pajamas, sitting on four different-colored but otherwise identical beanbag chairs, munching away on popcorn (or maybe Pringles). That’s probably not how it happened, but let me have my fun.