Twin Cities music fans were on the road again Friday afternoon to western Wisconsin for Willie Nelson's touring Outlaw Music Festival, the first major concert at Somerset Amphitheater since well before COVID-19.

The nearly forgotten outdoor concert and camping venue in Somerset — revitalized this summer with concert megacorporation Live Nation — made a messy, misstep-filled comeback, but the night's headliner sure did pass the test of time.

The last of the show's four opening acts — Robert Plant and Alison Krauss and their Grammy-winning revisionist band — similarly offset the hassles of getting to the show. So did homegrown heroes Trampled by Turtles and California roots-music maestro Molly Tuttle — though many of the nearly 20,000 attendees were still stuck in the hour-plus parking logjam when they took the stage.

At 90, Nelson had to sit for the duration of his set, which he capped at only an hour. He also had to rely on his son Micah Nelson, 33, to intermittently sing three songs to provide some breathing room.

However, those signs of diminishment were whitewashed by all the timelessly distinguishing traits still on display : the warm tone of his equally worn-down acoustic guitar, Trigger; the nasally operatic voice, which has lost a lot of its range but is still unmistakably Willie; and, of course, the trove of classic songs.

Nelson picked through 15 standards and a handful of surprises, starting (as always) with "Whiskey River" and ending with Hank Williams' "I Saw the Light." In between came (in order) "Bloody Mary Morning," "Mammas Don't Let Your Babies Grow Up to Be Cowboys," "On the Road Again" and "Always on My Mind."

Lesser-known tunes included the perfectly suited Rodney Crowell/Chris Stapleton co-write "I'll Love You Till the Day I Die," which Nelson recorded on last year's tender "A Beautiful Time," his 72nd studio album (!).

Micah's songs also broke from tradition but still fit the Willie mold — most notably "Die When I'm High (Halfway to Heaven)," the refrain of which, "If I die when I'm high I'll be halfway to heaven," was not surprisingly first mouthed by Willie, Micah explained.

Micah's presence helped keep up the "family" vibe of Willie & Family, following the death last year of Willie's piano-playing big sister Bobbie Nelson. The only longtime Family band member still in tow, harmonica player Mickey Raphael, sounded as invaluable as ever as he blew out solos in "Angel Flying Too Close to the Ground" and "Georgia on My Mind."

The opening acts became part of Willie's Family: The Trampled by Turtles crew and Tuttle and her band joined him near show's end as a beautifully ragtag choir for the gospel standard "I'll Fly Away."

"It's nice to be an honorary outlaw for the weekend," Trampled frontman Dave Simonett enthused during his Duluth-reared acoustic string band's breezy hourlong opening set. Songs from last year's more sonically expansive album "Alpenglow" were highlights, as was a cover of Low's "Days Like These" accompanied by its co-originator Alan Sparhawk — coincidentally or not, known to be a favorite of Robert Plant's.

Plant's collaboration with Krauss — never before seen in or around the Twin Cities — highlighted the entire festival.

Working with a stalwart band that included Oklahoma star JD McPherson on retro-fuzzy guitar, the two seemingly mismatched golden-voiced singers put a vibrant, new twist on Americana music in groovy, electro-rootsy reworkings of the Everly Brothers' "Gone Gone Gone" and the Lucinda Williams-popularized "Can't Let Go." Even wilder revisions were made of Plant's old Led Zeppelin songs, including a twanged-up "Rock and Roll" and a long, haunting "The Battle of Evermore."

In addition to the nearly hourlong battle for onsite parking spaces — and that's not counting the bottleneck outside the venue on Somerset's under-construction Main Street — the reopened amphitheater suffered from long food lines and sticker shock at the beverage stands. Corporate brand beers were $17, and margaritas $19. Makes you wonder who the "outlaws" were Friday night.