It's been 40 years since he left the Hollies, a British group, to add the magical third harmony part behind David Crosby and Stephen Stills.
Nash provided more than high harmonies for Crosby, Stills, Nash and (sometimes Neil) Young. His steadying influence often is cited in helping keep the group together. He also wrote some of the band's most memorable hits, including "Teach Your Children," "Our House" and "Marrakesh Express."
Like the other members of the group, he was embroiled in the political and social activism of the times, reflected in songs, such as "Military Madness," "Chicago" and "Immigration Man."
That passion remains in Crosby, Stills and Nash.
"Our fans will be surprised," Nash said. "They will see a passion they may have thought had disappeared in most bands -- but not in this one."
Nash, who lives in Hawaii, is out touring with CSN this summer.
He took time out during a tour stop in Seattle to talk about the group.
He says CSN's social conscience is in tact. For the past 10 years, the group has added an extra dollar to its ticket prices, which it divides among favorite charities. The quartet (with Young) performed together on the Freedom of Speech tour in 2006 and will reunite Sept. 27 in Oakland, Calif., for a benefit for the Seva Foundation, which aims to end world poverty and was co-founded by their pal, Wavy Gravy.
The band members appear to have checked their infamously huge egos and mellowed with age.
"We're singing some of the acoustic stuff around one mike, which may be a small thing to you but to us it's an enormous step," Nash said. "It means that we like each other. We can stand next to each other. We can get the blend in the way we used to do originally.
"It's different this tour. I think the older we're getting the more compassionate we're getting and the more understanding of our weaknesses we are getting, and the more supportive of our strengths we're getting. I think we're getting smarter."
Band members also appear to have put addictions and health problems behind them. The group is healthier, Nash says. "Steve lost 25 pounds. Dave lost 55. We're trying to grow up."
Nash isn't growing old gracefully. "I rarely sleep," he said. "I'm not a great sleeper. My brain just continues to move. I find it very difficult to sleep at night and calm my mind down. I have so many ideas. With all due respect, I'm 66. How much longer have I got? Ten, 20, 30 years? I've got (stuff) to do, man."
When Nash isn't touring, he's busy compiling box sets for the group and its members. He says he has 13 projects under way, among them:
□ An acoustic show Nash and Crosby performed in 1993. "That's phenomenal music."
□ A boxed set of his own recordings from 1964 to the present. In addition to his solo work and hits for CSNY, Nash wrote such tunes as "King Midas in Disguise" for the Hollies.
□ A boxed set of CSN demos. "When I was putting together a box set for CSN that came out 10 years ago, I found 54 of our demos."
□ A boxed set for Stills.