One is always on the road again, and the other is on a never-ending tour. But Willie Nelson's and Bob Dylan's concert-playing days might finally be numbered — which makes the announcement they're performing together at Somerset Amphitheater in September all the more momentous.

Dylan, 82, is joining Nelson, 90, on another installment of the country music icon's roaming Outlaw Music Festival, which will hit the outdoor venue near the Twin Cities in Somerset, Wis., on Sept. 6. They will also be joined by another Rock & Roll Hall of Famer at the show, John Mellencamp.

Tickets for the Americana music trifecta song fest go on sale this Friday at 10 a.m. via outlawmusicfestival.com, where presale options begin Tuesday. Prices are not yet available.

Nelson brought his Outlaw Music Fest to Somerset Amphitheater last year with a lineup also featuring Robert Plant and Alison Krauss and Trampled by Turtles. The caravan-like tour is a precursor to the Farm Aid fundraiser festival that he puts on every year in late September in different locations with co-founder Mellencamp.

The Somerset gig will be the Texas music hero's second show near the Twin Cities in 2024. He is also scheduled to play Bayfront Festival Park in Dylan's birth city, Duluth, on May 23. Only resale tickets to that one are available now.

Dylan, on the other hand, hasn't been seen playing in or near his native state since before the COVID-19 pandemic. His last gig in Minnesota was at Mankato Civic Center in October 2019. He returned to the road in 2021 with a mostly new band and has been earning largely positive reviews, with set lists heavily featuring songs off his last album, 2020′s "Rough and Rowdy Ways."

Friends for decades — Bob played the first Farm Aid in 1985 after planting the seed for it in Willie's head — Dylan and Nelson have performed together in Minnesota several times before, including tours of minor-league ballparks that hit St. Paul's Midway Stadium and Rochester's Mayo Field in the mid-2000s. Dylan recently paid respect to his old friend when he gave an unannounced performance at last year's Farm Aid with members of Tom Petty's Heartbreakers serving as his backing band.