
Patty Griffin, Robert Plant and Frank Melfi

Robert Plant and Patty Griffin perform onstage at the 13th annual Americana Music Association Honors and Awards Show at the Ryman Auditorium on September 17, 2014 in Nashville, Tennessee

Robert Plant and Patty Griffin perform onstage at the 13th annual Americana Music Association Honors and Awards Show at the Ryman Auditorium on September 17, 2014 in Nashville, Tennessee

Robert Plant and Patty Griffin perform onstage at the 13th annual Americana Music Association Honors and Awards Show at the Ryman Auditorium on September 17, 2014 in Nashville, Tennessee

Robert Plant and Patty Griffin perform onstage at the 13th annual Americana Music Association Honors and Awards Show at the Ryman Auditorium on September 17, 2014 in Nashville, Tennessee

Robert Plant and Patty Griffin perform onstage at the 13th annual Americana Music Association Honors and Awards Show at the Ryman Auditorium on September 17, 2014 in Nashville, Tennessee

Robert Plant and Patty Griffin perform onstage at the 13th annual Americana Music Association Honors and Awards Show at the Ryman Auditorium on September 17, 2014 in Nashville, Tennessee

Robert Plant and Patty Griffin perform onstage at the 13th annual Americana Music Association Honors and Awards Show at the Ryman Auditorium on September 17, 2014 in Nashville, Tennessee

Robert Plant and Patty Griffin perform onstage at the 13th annual Americana Music Association Honors and Awards Show at the Ryman Auditorium on September 17, 2014 in Nashville, Tennessee

Robert Plant and Patty Griffin perform onstage at the 13th annual Americana Music Association Honors and Awards Show at the Ryman Auditorium on September 17, 2014 in Nashville, Tennessee

Patty Griffin and Robert Plant pose backstage at the 13th annual Americana Music Association Honors and Awards Show at the Ryman Auditorium on September 17, 2014 in Nashville, Tennessee

Patty Griffin and Robert Plant pose backstage at the 13th annual Americana Music Association Honors and Awards Show at the Ryman Auditorium on September 17, 2014 in Nashville, Tennessee