See Emmylou Harris' Gorgeous Steve Earle Cover on 'Colbert'

Country Music Hall of Fame member also sang on original bluegrass version of Earle's 1999 "Pilgrim"

Emmylou Harris performs Steve Earle's "Pilgrim" on 'The Late Show With Stephen Colbert.'

"This song is for the over 65 million displaced persons around the world." That's how singer-songwriter and humanitarian Emmylou Harris introduced this breathtakingly beautiful performance of "Pilgrim," accompanied by her band, the Red Dirt Boys, on The Late Show With Stephen Colbert Monday night.

Written by Steve Earle and originally included on The Mountain, Earle's 1999 bluegrass LP with the Del McCoury Band, that version of the tune featured an all-star chorus which included Harris, along with Cowboy Jack Clement, Gillian Welch, David Rawlings, Marty Stuart, John Hartford, and many others.

"If you're a songwriter, you always wanted her to record one of your songs," Earle said of his longtime friend during a star-studded 2015 tribute concert honoring the country legend. Harris is currently celebrating the vinyl release of her 1992 LP, At the Ryman, which opened with her rendition of Earle's classic, "Guitar Town." Earlier this year, she reunited with her then-band, the Nash Ramblers, to perform the live album in its entirety.

The Country Music Hall of Fame member is also among the acts featured on an upcoming tribute album to songwriter John D. Loudermilk, whose classic compositions include "Tobacco Road," and "Indian Reservation."