Forty years ago today (May 8, 1982), Willie Nelson probably only had one thing on his mind: celebrating his latest single, "Always on My Mind." On that date, the song became Nelson's eighth No. 1 hit.

Written by Johnny Christopher, Mark James and Wayne Carson, "Always on My Mind" was the title track of and debut single from Nelson's 30th studio album. While the song has become one of the Texan's signature tunes, he is just one of several artists who found success with "Always on My Mind;" others include Elvis Presley, Brenda Lee, John Wesley Ryles and the Pet Shop Boys.

"I wrote those two verses living in Springfield, Mo.," Carson recalls. "I’ll think of the melody or the chord structure or something I’ll come up with, and I’ll make — I’ll see if that doesn’t fit the words or anything like that. If the melody is singable, the words are not far away. It’s only a story, you know.

"In this case, "Always on My Mind" happens to be one of those things that, universally, everybody on the planet has been there, you know. And it struck all at one time," he adds. "Everybody touched base with that one. It was just magic that it was so simple and so right on the button."

"Always on My Mind" stayed on top of the Billboard Hot Country Singles chart for two weeks, before Nelson's duet with Waylon Jennings, "Just to Satisfy You," claimed the top spot instead. The Always on My Mind album, meanwhile, earned Nelson Album of the Year at both the ACM Awards and CMA Awards, and the song took home trophies for Single of the Year as well. Nelson also won a Grammys trophy for Best Country Vocal Performance, Male.

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