Ray Lamontagne, right, and bassist Zack Hickman perform at DAR Constitution Hall in Washington, D.C. (Kyle Gustafson/For The Washington Post)

Two-thirds of the way through his Friday night concert at DAR Constitution Hall, Ray LaMontagne forgot the words. Smack in the middle of “Empty,” a song from his 2006 album “Till the Sun Turns Black,” he called upon the audience for help with the lyrics and lumbered and hummed his way through it.

“There’s just so many songs at this point,” he said sheepishly, choking back laughter. “I’m not making excuses, it’s very unprofessional. There’s really just so many words . . .

Nobody cared, of course; his performance during the rest of the two-hour set more than made up for it. If anything, the slip-up only made LaMontagne, who is even more arresting live than on his albums, seem a bit more human.

The show was labeled “An Acoustic Evening With Ray LaMontagne,” and much like the man, it was a simple affair. He wore faded denim from head to toe and began the show without a word. His only company was stand-up bassist Zack Hickman, and the set was a wall of crooked wooden doors, a gramophone, a coat rack with a lone hat and a few empty boxes. It was exactly what you’d imagine LaMontagne’s living room might look like: stark, old-fashioned and isolated.

Therein lies the lure of LaMontagne: A lanky woodsman with a reclusive sensibility and cruelly seductive pipes, he remains uncontaminated by fame.

His path to stardom was peculiar and often painful. Growing up poor and sometimes homeless, he was one of six children to a single mother in Maine. It wasn’t until his alarm went off one morning to the tune of Stephen Stills’s “Treetop Flyer” that he left his job at a shoe factory to follow music’s call.

Thirteen years and four albums later, the 39-year-old still doesn’t seem entirely comfortable in the spotlight. He fumbled through stories about shoddy old recording studios and deflected flattering screams from the audience (“No, you’re the beautiful one,” he purred), all while fiddling with his guitar. And when he sang, he turned sideways to face Hickman, as if those extra 45 degrees might help him forget about the audience and get into the zone.

When he does, he’s invincible — and irresistible. Women howled as he leaned into sensual love songs such as “Let It Be Me” and “Roses and Cigarettes,” hollered through the grittier confessional ballads like “Old Before Your Time” and “Beg, Steal or Borrow.” And during his breakout hits “Trouble” and “You Are the Best Thing,” the music hall swelled with high-pitched sighs.

But LaMontagne’s success isn’t based on sympathy or sex appeal. He’s deeply talented, unassuming and seeks to return the love he is given.

“I know you guys like me,” he said. “I just don’t take it for granted.”