Every 80 years or so, I try to have a meaningful conversation with Graham Nash — which is to say that Nash, who in February turned 80, allowed me to interview him in 2017.

Only 77 years till the next time!

It was a pretty great conversation, at least from my perspective, because Nash went into detail about the acid trip he took that spawned the song "Cathedral," which is my favorite of a whole hell of a lot of great tunes he wrote. Suffice to say, Nash — who as most people born in this galaxy know was a member of Crosby, Stills, Nash (and Young) and the Hollies and is a solo star — took the LSD and went to Stonehenge and then Henry VIII's Winchester Cathedral, where King Arthur's apocryphal roundtable hangs on the wall.

Think about that! This wasn't a few bros smoking some Thai stick and watching a Cheech & Chong movie; this was broadening the senses by psychotropically diving into Big Moments in English history! No wonder Nash wrote a song about it.

Well, if one's going to dip into Nash's musical history, here's hoping you have tickets for his sold out shows at The Kate Monday and/or Tuesday. He's bringing a fine band to perform a generous retrospective of his life's work. And, yes, "Cathedral" is on the set list.

Graham Nash, 7:30 p.m. Monday and Tuesday, Katharine Hepburn Cultural Arts Center, 300 Main St., Old Saybrook; sold out; www.thekate.org. (860) 510-0453.