John Mayer made a magical moment for fans who attended his concert in Nashville Tuesday night (Aug. 8). The singer-songwriter and guitarist broke out a surprise cover of Glen Campbell's "Gentle on My Mind" in tribute to the departed legend.

Mayer performed at the Bridgestone Arena as part of his Search for Everything Tour, offering fans a diverse night of music that included a full band set, a set with the John Mayer Trio and a solo acoustic section. During the latter section he addressed the crowd, saying, "I'm going to play this song with more love than precision. And I play it because it's my favorite song in the world."

"Whether I play it right or wrong, I'd rather have played it," he added.

Mayer then launched into "Gentle on My Mind," a John Hartford song that Campbell made into a career hit with his 1967 recording. Campbell's rendition won him Grammys for Best Country & Western Solo Vocal Performance, Male and Best Country & Western Recording. Hartford also won Grammys for Best Folk Performance and Best Country & Western Song for "Gentle on My Mind."

In the fan-shot video above, Mayer certainly doesn't appear to be having any trouble as he handles the difficult fingerpicking progression superbly, coupling it with an understated vocal performance that — like Campbell's original — does not overpower the unique lyrical structure or gentle melody of the song.

Kelsea Ballerini was in the audience for Mayer's stunning musical moment, and she reacted to it on Twitter, calling it "tender and beautiful."

Glen Campbell died on Tuesday (Aug. 8) in a Nashville care facility after battling Alzheimer's since 2011. He was 81 years old. Tributes have come pouring in from all quarters of the entertainment world, including one from Keith Urban, who lauded Campbell for his  "Universal music, universal stories, universal spirit. No wonder he was a global superstar," Urban adds. "I love Glen for so many reasons — but above all, for his humanity."

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