Willie Nelson is a powerful musical force, as all of his fans know. The 85-year-old legend showed off some of his magical influence Aug. 9 at Southern California's Orange County Fair, when he managed to get an old friend of his back on stage for the first time in nearly a decade.

"My good buddy Jessica Simpson and I are gonna sing a song together,” Nelson, who co-starred with Simpson in The Dukes of Hazzard movie back in 2005, informed the crowd during his set.

A beaming Simpson took the stage, gave Nelson a warm hug, and the two broke into a brand-new, verse-trading song "I Will Be Your Fool." (Nelson informed the crowd that he'd recently recorded the song with Simpson, but didn't elaborate on when it would be officially available.)

Simpson, whose singing career is rooted in pop, hasn't sang on a stage in nine years—she's moved on to other pursuits, such as fashion design and taking care of her two young children—but she seemed right at home singing with Nelson.

She clearly enjoyed the moment as well, posting a shot to Instagram in which she noted, "It's not every night that a legend invites you to join him on his stage."

In 2008, Simpson—who portrayed the iconic Daisy Duke in the Dukes of Hazzard remake film—did release a country album, Do You Know, which debuted at No. 1 on the Billboard country chart but sputtered out quickly. Her last singing performances included a stint opening for Rascal Flatts in 2009.

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