Crosby Stills Nash & Young

"The best thing that ever happened to CSN was Neil, and the worst thing that ever happened to CSN was Neil."

"At this point, it's not about would we get together," he says. "Should we, is the important question."

Defining folk rock is a paradoxical task, to say the least.

He wrote "I Watched It All Come Down" to express his regret they didn't do more together.

"His legacy will continue to live on through his legendary music," Crosby's wife said in a statement.

Singer admits his actions "pretty much destroyed" the group.

"Stephen [Stills] and Neil [Young] and I are great," Nash told 'CBS Sunday Morning.' "We talk often. We don't talk to David."

Four CDs will feature numerous outtakes, unheard alternate versions and an appearance from Joni Mitchell.

But he admits he still has problems with David Crosby, which don’t look to be resolved any time soon.

Seldom in rock history have four guys who seemingly couldn’t stand each other sounded so good together.

Trio brought Neil Young on board shortly after releasing their debut album.

It wasn't long before they were back to fighting again.