Tony Bennett has been making the rounds this week promoting his new Duets II album and talking about how he wanted to save late singing partner Amy Winehouse by telling her to slow down, to take it from someone who'd already been there and had gotten the same advice from his idol, Frank Sinatra.

That kind of been-through-the-fire mentoring is a time-honored tradition in the music world, one that came to mind again on Wednesday when long-running alt rock godheads R.E.M. announced they were packing it in after 31 years in the midst of the 20th anniversary celebration of Nirvana's groundbreaking Nevermind album.

You see, enigmatic R.E.M. singer Michael Stipe had been through the superstar crucible. The intensely private frontman who spent a good early portion of the band's career mumbling his cryptic lyrics while hiding behind a scraggly veil of wavy hair knew all about the pressures of fame by the time Nirvana were having their world-exploding "Smells Like Teen Spirit" moment.

One thing ends as the dawn of another is celebrated.

It's a rock circle of life that was clearly not planned, but has a very nice, round arc to it. It connects these two bands yet again, providing another reminder that it was because of the hard work of acts like R.E.M. that Nirvana was able to blast out of the Northwest and take on the world.

The coincidental chapters also recalled the fact that Stipe had gone from indie darling to worldwide rock star just months before Nevermind hit in late 1991 thanks to the breakout success of "Losing My Religion," the first single from R.E.M.'s seventh album, Out of Time.

In the ensuing years, the two men would carry on a kind of public mutual-admiration society, as Nirvana singer Kurt Cobain went to great lengths to praise R.E.M.'s influence on his own band. And critics couldn't help but notice how, like R.E.M., Nirvana had managed the tricky tightrope walk of retaining their indie edge while signing to a major label and making polished, pop-influenced music with gritty bite and uncompromising lyrical flavor.

Stipe seemed to gladly take on the role of mentor, perhaps seeing in Cobain's adoration tinges of the same relationship he had with his idol, punk godmother Patti Smith, whose influence Stipe praised publicly at every turn.

"I don't know how that band [R.E.M.] does what they do," Cobain said in a 1994 Rolling Stone magazine interview. "God, they're the greatest. They've dealt with their success like saints, and they keep delivering great music."

By 1994, Stipe, like many in Nirvana's inner circle of friends and management, had grown concerned about Cobain's dangerous drug spiral. In an attempt to try and bring Cobain back from the abyss, Stipe — the godfather of Cobain and wife Courtney Love's only child, Frances Bean — planned a collaboration with the doomed grunge singer.

"I was doing that to try to save his life. The collaboration was me calling up as an excuse to reach out to this guy. He was in a really bad place," Stipe told Interview magazine earlier this year. "I constructed a project to try to snap Kurt out of a frame of mind. I sent him a plane ticket and a driver, and he tacked the plane ticket to the wall in the bedroom and the driver sat outside the house for 10 hours. Kurt wouldn't come out and wouldn't answer the phone."

The superstar hookup never happened and — like Neil Young, Smith and numerous others — Stipe was inspired to write a musical eulogy for Cobain, the moving 1994 song "Let Me In," from the album Monster. Fittingly, that disc found R.E.M. adopting a grungier, harder-edge, distorted sound that went the opposite direction of their two more sedate, previous mainstream breakthrough efforts.

Once again, the celebration of a beginning and a sad ending that can forever link these two legendary acts.

Stipe grew gracefully into the role of alt-rock elder statesman, enduring the rigors of stardom with wit and confidence. "A wise man once said--'the skill in attending a party is knowing when it's time to leave,' " he wrote in a statement announcing the band's end. "We built something extraordinary together. We did this thing. And now we're going to walk away from it."

Cobain, on the other hand, was swallowed up by the machine, prematurely putting an end to his story and walking away from the party way too early. Maybe if he'd had that sit-down session with Stipe he might have managed the dream he shared with us in a 1993 interview. "I wanted to have the adoration of John Lennon but have the anonymity of Ringo Starr," Cobain told MTV News. I didn't want to be a frontman. I just wanted to be back there and still be a rock and roll star at the same time."

Stick with MTV News all week as we reveal the Nevermind You Never Knew, celebrating the 20th anniversary of Nirvana's definitive album with classic footage, new interviews and much more.