Toby Keith and Willie Nelson teamed up to perform an epic cover of Merle Haggard's "Rambin' Fever" at the Sing Me Back Home: The Music of Merle Haggard tribute concert in Nashville on April 6. Click play above to watch the duo perform Haggard's 1977 hit, and scroll down to check out a special solo performance from Keith.

Originally released as part of Haggard's 1977 album of the same name, "Ramblin' Fever" is characterized by the country icon's signature songwriting, which reads like a story, and his ability to portray bravado and compassion in the same breath. When lyrics such as "If someone said I ever gave a damn, they damn sure told you wrong" combine with the quavering warble of Haggard's vocals, listeners can't help but wonder if he really does care more than he lets on.

During Sing Me Back Home: The Music of Merle Haggard, Nelson made multiple appearances onstage, performing hits from his and Haggard's 1983 collaborative record Pancho & Lefty as well as solo-Haggard hits such as "Rambin' Fever." Along with his appearance with Keith, Nelson also performed "Pancho and Lefty" with Kenny Chesney and “Reasons to Quit" with Keith Richards of the Rolling Stones.

Keith also performed more than once during the special concert event, taking the stage a second time for a solo performance of Haggard's 1971 chart-topper "Carolyn." Originally released as the second single from his Someday We'll Look Back album, the song earned Haggard his 11th No. 1 hit and was the perfect tune for Keith to perform in his honor.

Other artists who took the stage to honor Haggard during Sing Me Back Home: The Music of Merle Haggard included Dierks Bentley, Miranda Lambert, Jake Owen, Chris Janson, Sheryl Crow and Loretta Lynn. A portion of the proceeds from the event benefited the TJ Martell Foundation.

Watch Toby Keith Perform "Carolyn" in Honor of Merle Haggard

10 Essential Merle Haggard Lyrics