"Trad is Rad again," suggested festival organizer and Philadelphia Folksong Society president Lisa Schwartz. "Folk's gone from being a four-letter word to being the next big thing, thanks to artists like Mumford and Sons, the Lumineers and the Avett Bros."
So, with no seller's remorse, this coming weekend's fest will serve a savory potpourri, including:
* A blues 'n' funk fix of Shemekia Copeland, Josh White Jr. (honoring the centennial birth of his dad) and New Orleans' rompin', stompin' Rebirth Brass Band.
* Variations on Old World charm with Cape Breton fiddler Natalie MacMaster, Scottish singer Archie Fisher and Celt-rockin' vets Tempest.
* Singer/songwriter icons Loudon Wainwright III and Janis Ian, plus charismatic new kids on the block the Lone Bellow and the dynamo duo Johnnyswim - a/k/a Abner Ramirez and Amanda Sudano. She's a Nashville "folkie" who cut vocal chops singing backup for Mom, Donna Summer.
* Most significantly (for the Mumford/Avett fan base), this festival's leaning extra heavily on groups who likewise qualify as young 'n' hip, yet "old timey," too - talents not just reviving but also reshaping the ways of rustic country, hillbilly rock and bluegrass (the fleet-fingered, showboating side of acoustic country music).
We're talking about such festival 2014 visitors as Jason Isbell (of Drive-By Truckers fame) and Kentucky coal miners' offspring Sturgill Simpson, a major buzz recently showcased by David Letterman. Simpson's band headlines the first "early-birds" concert for PFF campsite arrivals Thursday night and also will play off the fest grid at Ardmore Music Hall on Friday.
Then there's shockingly successful string-band crossovers Old Crow Medicine Show, closing the fest's first mainstage show Friday evening. Won't be surprised to see fans up and dancing like they're jamming at a Phish concert, especially when the guys roll out their big-hit writing collaborations with Bob Dylan, "Wagon Wheel" and "Sweet Amarillo." Old Crow's grown so popular and influential, "we're bending the rules, giving them 70 minutes to play," said Lundy.
But wait, there's more
Sawing fiddles and glistening geetars also will be sizzling for a noon set Saturday with Texas-swingsters Hot Club of Cowtown, then later in the day by frisky, freaky backwoods boys the Brummy Brothers.
And Sunday's-into-night talent lineup is especially strong with string-driven things - including an Old Time Banjo workshop at noon, a multi-act showcase on the tented lobby stage at 1:30 p.m., then the mainstage show (starting at 4) that includes (among others) 23-year-old music masher Sarah Jarosz (think Texas troubadour, conservatory cultured), Mr. Isbell and the Steep Canyon Rangers - bluegrass blades often working (though not here, drat) with Steve Martin and Edie Brickell.
So what's the glue connecting all these talents?
"These performers have found a way to create something completely unique out of something that seems really familiar," opined Schwartz.
"We started young [in 1998], and we've never done things like other bands," shared Old Crow Medicine Show co-founder Critter Fuqua, in a recent chat. "I didn't grow up in Virgina listening to bluegrass. I wasn't a sharecropper. I listened to punk rock, Guns 'n Roses. For me, Nirvana was a roots band. Roots is tapping into something that's real, honest, meaningful. That's how we approach string-band music. It was brand new once - maybe in colonial Jamestown, maybe when the slaves landed from Africa bringing and introducing the banjo to America. And even today, you can still bring a lot of fresh attitude, energy and edginess to it."
Having some youthful fearlessness doesn't hurt either, Critter added, with a laugh. He was 17 when he discovered a "snippet" of "Wagon Wheel" on a Bob Dylan bootleg. "It was an outtake [originally called "Rock Me Mama"] from the score he wrote for the  movie 'Pat Garrett and Billy the Kid,' but it fell by the wayside next to the movie's big hit 'Knockin' on Heaven's Door.' So we took it upon ourselves to finish the song, then sent it to Dylan for approval - which he mostly did, with a few alterations. As [Dylan's] son Jakob later noted, we'd probably never have had the courage to do all that if we were 'older and wiser' and really thought it through!"
With the title of his new album, "Metamodern Sounds in Country Music," Sturgill Simpson is clearly pondering what it means to be a 36-year-old talent in today's rapid-change digital age whose inspirations are long gone and rarely connected - from Waylon Jennings to Jimi Hendrix. But connect the dots he does between those outlaws past, with a down-home, sometimes psychedelicized country sound and lyrical constructs to match.
"Some people think I'm talking about drugs or TM [transcendental meditation] but, really, the whole record is about universal consciousness and love," he said last week.
The "metamodern idea" is partly a nod to Ray Charles' landmark 1962 album hybrid, "Modern Sounds in Country and Western Music," Simpson conceded. But the term also nods to "a deep thinker named Seth Abramson - look him up - and his thesis on the oscillation of modern culture between naivete and our love for nostalgia, for an America that maybe never really existed."
Simpson says that he's sharing from the heart, hoping that "young people who hear me first will then go out in search of Willie [Nelson], or Waylon Jennings & the Strangers albums. I tried to make a honky-tonk country record - rough-hewn, cut fast and all analog - like I wasn't hearing anymore."
But in the next breath he fears the motivations of some other old timey newcomers - "the Brooklyn hillbillies, the suspender-wearing fashionistas who seem more focused on the appearance than the substance in the songs. This movement should be about chops, about keeping the real music alive."
Philadelphia Folk Festival, Old Pool Farm, Clemmers Mill Road & Salford Station Road, Upper Salford Township, Schwenksville, Pa. Camp stage concert Thursday at 7:30 p.m (open only to weekend/camping ticket holders), Friday-Saturday, 10:30 a.m.- midnight, Sunday, 10:30 a.m. to 9:30 p.m., Admission info: 1-800-556-FOLK, pfs.org or folksong.ticketleap.com.
Sturgill Simpson also plays Ardmore Music Hall, 23 E. Lancaster Ave., 8 p.m. Friday, $14-$18 (21+), 610-649-8389, ardmoremusic.com.