Scan the list of winners at the Americana Music Association's 7th Annual Honors & Awards show, held Thursday at Nashville's Ryman Auditorium, and you might think you've stumbled into a rock 'n' roll time warp. Among the night's top honorees at one of Music City's hippest, most genre-bending awards shows after all, were former Led Zeppelin lead singer Robert Plant and The Band drummer Levon Helm.

The three-hour ceremony, which also featured performances by lifetime achievement honorees Jason and the Scorchers, Joan Baez and John Hiatt, included actor/musician Billy Bob Thornton and his bandmates, the Boxmasters, presenting the Artist of the Year award to Levon Helm. At the close of the show, Helm and several of the award recipients offered a musical tribute to President's Award winner Jerry Garcia, of the Grateful Dead.

In one of the evening's more comical moments, Robert Plant, who took the stage to pick up two awards with Alison Krauss for their collaborative effort, 'Raising Sand,' recalled playing with his "other band" in Nashville "thirty or forty years ago," during which they received the key to the city, then were quickly put under house arrest. He added, jokingly, that the incident may not have happened in Nashville after all, but in some other city.

On hand to present a Trailblazer Award to Nanci Griffith, whose records he produced in the late-1980's, Tony Brown -- best known today for producing Reba McEntire and George Strait -- was surprised with his own Lifetime Achievement Award.

The show, which also aired live on XM Radio was bookended by two fiery performances: the kings of country-punk Jason and the Scorchers lived up to their incendiary name, and soulful New/Emerging Artist of the Year, Mike Farris, offered up a jubilant version of "Mary Don't You Weep."

Jim Lauderdale returned as host of the awards show, with Buddy Miller as leader of the house band. Other performers included Ryan Bingham and Joe Ely, The Sam Bush Band, Kieran Kane, Kevin Welch and Fats Kaplin, The SteelDrivers, Tift Merritt, Chris Thile and Edgar Meyer, Justin Townes Earle, James McMurtry, and Steve Earle and Alison Moorer. Robert Plant also joined Buddy Miller for the performance of a track the two recorded for Miller's album, due early next year.

The awards show is the centerpiece of the Americana Music Association's four-day conference, attended by radio programmers, music-industry professionals and fans of the rapidly-growing music format from all over the world.

Complete List of Americana Award Winners and Honorees:

Album of the Year: 'Raising Sand,' Alison Krauss & Robert Plant

Artist of the Year: Levon Helm

Duo/Group of the Year: Alison Krauss & Robert Plant

Instrumentalist of the Year: Buddy Miller

New Emerging Artist of the Year: Mike Farris

Song of the Year: "She Left Me for Jesus" by Hayes Carll and Brian Keane

Spirit of Americana Free Speech in Music - Joan Baez

Lifetime Achievement / Songwriting - John Hiatt

Jack Emerson Lifetime Achievement (Executive) - Terry Lickona

Lifetime Achievement (Performance) - Jason & The Scorchers

President's Award - Jerry Garcia

Lifetime Achievement (Instrumentalist) -Larry Campbell

Trailblazer - Nanci Griffith

Lifetime Achievement (Producer/Engineer) - Tony Brown