In 1968, Graham Nash – then known, if he was known at all, as a member of the pop group, the Hollies – flew from the UK to California to spend some time with his girlfriend, Joni Mitchell.

When Nash entered her home in the Hollywood hills, he heard music being played by two men he’d met but did not know: Stephen Stills, formerly of Buffalo Springfield, and David Crosby, formerly of the Byrds.

This unofficial American duo performed for Nash a song that Stills had written called “You Don’t Have to Cry.”

Nash asked them to play it again and then a third time, not just because he liked it but because he heard something in it or something that should have been in it.

On the third go-round, Nash added his voice to theirs.

Forty seconds later, Nash told me in a phone interview, the trio stopped, stunned.

“That was an incredible 40 seconds,” he said.

The three men were all Everly Brothers fans who had imbued every project they’d undertaken up to that point with close harmony singing.

But the sound they made in Mitchell’s living room that day seemed new, Nash said.

Nash’s life utterly changed in that moment because CSN had appeared, fully formed, out of nowhere. Or next to nowhere.

He left the Hollies behind and moved permanently to Southern California.

Almost a half-century later, those three men are still making music together.

Nash is currently on the Midwestern leg of a solo tour that will bring him to the Murat Center in Indianapolis on Saturday, August 1.

Indianapolis attendees “can expect everything from the Hollies to the stuff I wrote that morning,” Nash said.

Last September, Nash released “Wild Life” (a memoir so accurately named that it may constitute an understatement) and he recalled having a curious reaction while proofreading the galleys.

“I looked down on it and I said ‘Holy Toledo. I wish I was him.’ It really seemed to me in that moment that it was about somebody else.”

Given the consummate wildness of that wild life, especially in the early days of CSN, it’s amazing that any of these men were able to make music at all.

“A lot of people say to us, ‘Would you have made more music or better music if you’d been less stoned or less egoed out?’ We’ll never know the answer to that question,” Nash said. “It is what it is. We were very high when we were making that early music. And that’s what it was.”

Of course, the wages of pharmacological sin are sometimes paid in increased creativity.

“Everything in moderation, kid,” Nash said.

It is one of the “Believe It Or Not” factoids of rock music that CSN, despite having formed in 1968, did not perform live until 1977.

That’s because the band, largely for practical reasons, had to become CSNY for a time.

Stills had handled the bulk of the instrumental work on CSN’s debut album, but the band needed to add some musical muscle for its first tour.

Enter Neil Young.

Having endured Young’s capricious and erratic behavior in Buffalo Springfield, Stills was against the plan to add Young at first, Nash said.

Nash had his own reservations, so he invited Young to breakfast one morning in New York City.

“I knew he was a great singer,” he said. “I knew who he was musically. I had no idea who he was as a person. And that, of course, is a very important ingredient.

“It wasn’t until that breakfast that I just loved him,” Nash said. “He was very funny. He was very self-secure. He was very compassionate. He was everything I wanted in a partner. He was great.”

CSNY did end up making much beautiful music together. Nash said it was unearthly at times to stand on stage and listen to the interplay of Young’s and Stills’ guitars.

But Nash said the foursome was, to quote Crosby, like “juggling four bottles of nitroglycerine.”

Young has always held himself at a distance from the other men (Indeed, as is chronicled in the book, he has sometimes mistreated them, intentionally and unintentionally).

“Neil is a solo human being,” Nash said, “The three of us had a friendship…well, we were like brothers. The three of us were very close and it was very difficult to slip Neil in between all that stuff but we managed to do it.”

The trio has had its ups and downs over the years, including Crosby’s bout with drug addiction and subsequent jail stint and liver transplant.

But Nash said they are now sounding better than ever.

“We’re certainly stronger together and that’s very important for harmony singing,” he said. “We are very much liking each other these days.”

Nash has a new solo album coming out in the spring and he said that he and Crosby are putting together a compilation of songs they’ve performed with other artists including Mitchell, Bonnie Raitt, Carole King, James Taylor and Phil Collins.

Nash said he writes new material in bursts and can’t rush the process.

“I get moved by something and then have to go to my guitar or piano to express myself,” he said. “That’s what happens. I wake up in the morning. I’m breathing. I’m grateful to be alive and I get on with my day. I have to be moved before I can write.”

He does say, however, that he needs to “create every single day or else I can’t sleep.”

Even though the music business has changed greatly over the years, Nash’s advice to young musicians hasn’t.

“My advice has always been, ‘Go from your heart,’” Nash said. “Your heart knows whether it has something worth talking about or singing about. Your heart knows. Just go from there.”

Even the most pragmatic person must acknowledge the serendipity that brought Crosby, Stills and Nash together in Mitchell’s living room that day 47 years ago.

Nash acknowledges it and he said he takes nothing for granted.

“I love being alive,” he said.” I love being a creator. I love being a communicator. I’m a very lucky man, Steve.”