When U.K. folk-rockers Mumford & Sons first “broke” in the mainstream a couple of years ago, it felt like their name was on the tip of everyone’s tongue – including a number of famous fans.

Flash forward to today, practically the eve of their second album’s release (Babel is out Tuesday): Led Zeppelin frontman Robert Plant took time out of the band’s rare press conference to shine a light on Mumford & Sons. “I think Mumford & Sons excite me because they do have drama and they do have optimism,” he said. “They can turn a crowd upside down.”

Like fellow folkies Dawes, Mumford & Sons seems to be one of the most predominant new acts to be name-checked by rock’s royalty. Let’s take a look at which other musical icons have endorsed Marcus Mumford and his mates.

BOB DYLAN

At the 2011 Grammys, when Mumford & Sons were still fairly fresh in the American consciousness, they participated in a “tribute to acoustic music” alongside the Avett Brothers, another act helping to bring the banjo back. Oh, and Bob Dylan. The right-minute trio of songs was capped off by the three bands jamming on Dylan’s 1965 classic, “Maggie’s Farm,” the younger bands grinning ear to ear to simply be on the same stage as Dylan. For those who’d never heard of Mumford & Sons, that was their big moment, a lifetime association with folk’s greatest hero. Watch the performance here.

RAY DAVIES

To have Kinks frontman Ray Davies call you a friend is no small feat. And that’s exactly what Davies did in 2010, when he released his album See My Friends. For the album, Davies re-imagined his biggest hits with a guest list of pals including Bruce Springsteen, Jon Bon Jovi, Jackson Browne, Metallica – and Mumford & Sons. For their collaboration, Davies and Mumford mashed-up The Kinks’ “Days” and “This Time Tomorrow” with a wicked banjo line and dueling vocals. And it’s among the album’s best tracks.

NEIL YOUNG

Neil Young’s love does not come easily, but he seems to have some for Mumford. In recent interviews with Young, he praised the band (and rockers My Morning Jacket, a common favorite among classic rockers), saying, “I love them both and I know them well. I feel good about saying that.” Young seemed to feel good about Mumford & Sons last fall, when he performed with them at his annual Bridge School Benefit. Their song of choice? Young’s “Dance Dance Dance,” which Mumford has covered on tour.

- Jillian Mapes, CBS Local

(Grammy photo by Kevin Winter/Getty)