When Sam Barber wrote his first song, he had no idea how far it would take him. Just 16 at the time, the country singer/songwriter penned "Straight and Narrow," an aching, clear-eyed plea for resilience that revealed his old soul — and proved he's a star on the rise.

"Straight and Narrow," which appeared on Barber's 2023 EP, Million Eyes, was the now 21-year-old's first brush with viral success, racking up streams and drawing in fans who were intrigued by the young guitar slinger who seemed to appear out of nowhere. The song would eventually land on Billboard charts — in both rock and country — and helped Barber earn a Grand Ole Opry debut and a partnership with Atlantic Records.

Barber's latest milestone is his debut album, Restless Mind, which arrived Nov. 1. The double LP shows the true breadth of his artistry, which is grounded in raw, narrative songwriting — like that of two of Barber's musical idols, Zach Bryan and Tyler Childers — and gritty, spare production that puts the listeners' focus squarely on Barber's emotive, bellowing voice.

Barber says he originally planned to record around a dozen songs for the LP, but instead, Restless Mind comprises a whopping 28 tracks. While that volume was intentional, Barber wasn't trying to keep up with the double-album trend country music has seen as of late — he simply wanted to please his fans.

Though he just began sharing his music in 2021, Barber's rapidly growing fan base — who first loved him for his covers on TikTok — continuously asked for more music. He felt his listeners deserved as much from him as he could muster for his debut album, and as he tells GRAMMY.com, "I want them to know I am working very hard."

Barber describes himself as a prolific writer and that it's his love for songwriting, specifically, that motivates him. Restless Mind is "an accumulation of my entire music career up to this point," Barber says, adding that some material comes from his teen songwriting years while other songs are just months old.

At the helm of Restless Mind was producer Eddie Spear, whose creative partnership with Barber began in 2022 after Spear DMed the singer. As one of Zach Bryan's frequent collaborators, Spear's desire to work with Barber wasn't just "surreal" for the budding star, but also validated the work he'd created up to that point. Spear's involvement also helped Barber see his music in a new light.

"Eddie made my songs something that I never could have imagined, just putting extra pieces," Barber says. "And the people I met in the room… It opened my mind to a completely different world of music that I didn't even know was a thing."

One such world is pop. Barber and GRAMMY-winning songwriter Amy Allen, whose extensive list of credits includes cuts for pop stars like Harry Styles and Sabrina Carpenter, met at a co-write and found unexpected creative common ground. Though he initially felt skeptical that they could bridge the gap between their different styles, Barber left their session (which spawned Restless Mind's "Thought of You," as well as a few other unreleased songs) with an expanded sense of what his music could be.

Restless Mind opens with the honest and tender track "Man You Raised," inspired by Barber's close relationship with his mother. After sharing a snippet of a voicemail from her, Barber promises his mother not to let the freewheeling lifestyle of a touring musician get the better of him. A singer who sometimes favors feeling over precision, Barber wrings every last drop of emotion from the lyric, a move that characterizes the rest of the album.

While 28 tracks can be daunting, Restless Mind is thoughtfully sequenced, with other bits of scene-setting audio sprinkled throughout and offering natural resting points. "G-PA," for example, is a clip of Barber's grandfather speaking about how the singer's "mind is always on the move," and sets up the Avery Anna-featuring title track, which offers one of Barber's most haunting vocals.

Another highlight is "Bet on My Ghost," which takes cues from grunge and alt-rock with its droning opening riff and Barber's garbled delivery. "Down the Road" lightens the sonic mood, with a driving beat and rambling riff illustrating the restlessness at the heart of the lyric. Barber closes the LP with "You Know I Know," an ambivalent song about existential exhaustion that makes a drastic musical shift in its final minute — ending Restless Mind in both poignant and captivating fashion.

Barber's live show is equally as compelling as his music, and he suggests that time on the road has been especially educational as he navigates the ins and outs of both stardom and live performance. Before kicking off his headlining Restless Mind Tour in September, Barber has spent 2024 playing other headlining gigs as well as festival slots at Stagecoach, Railbird and Lollapalooza. And last year, he had the chance to learn from Ed Sheeran and Bruce Springsteen, both of whom Barber opened for on select dates.

"Ed wanted to show me that, no matter how large or big you are, people thinking you are just a good human being goes the longest way," Barber recalls. "It will get you as far as anything else."

Watching Sheeran perform was equally as impactful as his words of wisdom. "The way that he would go up on stage with just a guitar and completely control a crowd, the things he said and the emotion he could put out — everyone was dead silent, and it showed me that you don't need that much," Barber adds. "You just have to be a good person, [be] strong and know yourself. People see that."

Barber may rub elbows with big-name stars these days, but he says it's his family who truly fuels his creative fire. In fact, his late great-grandfather's musical history was what first inspired him to make music, and it was his mother who encouraged him to drop out of college in favor of pursuing music.

"My great-grandpa had played in bars and stuff," Barber says. "He had his old guitar in my parents' house, and that's what I picked up for the first time. I never got to meet him, unfortunately, but knowing that there was music in the family, it drove me."

He also calls his grandfather, who is still living, one of the "biggest supports and motivations" — and may be one of the biggest reasons Barber is wise beyond his years.

"He's the hardest working man I've ever met in my life," Barber adds. "He definitely showed me that anything is possible… He has nothing to do with music, but just seeing a man like that, it drives you every day. He's a wise man, holding a lot of very smart things and aspects to life that I would have never thought of without his encouragement."

As evidenced on "G-PA," Barber's grandfather may never have imagined all of this success for his grandson, either, but sometimes "straight and narrow" paths lead to unexpected places. Landing a hit with the first song you write is a dream come true for most aspiring artists — but for Barber, it's just the beginning.