By the time the sun dropped behind the downtown skyscrapers to the west of Gallivan Center, and the near-full moon rose over the mountains to the east, Saturday night was well on its way to becoming one of those perfect Utah evenings. And the charming, unpredictable Justin Townes Earle proved a fine choice to provide the soundtrack.

Earle was far from perfect, as he admitted during his between-song banter describing a couple of false starts on songs. But he's the kind of artist whose occasional mistakes only make his performances more engaging. And when he locks in, playing intricate, finger-picked guitar and delivering heartbreaking examples of some of the best roots-based songwriting around, Earle is something to see, and hear.

Playing sans band and sporting a summery short-sleeved polo, Earle was the closer of the day-long folk and bluegrass festival thrown by the Intermountain Acoustic Music Association. You could tell much of the crowd wasn't familiar with Earle's music--even his introduction to the stage consisted of a guy reading what sounded like a Wikipedia entry--but there was also a slew of familiar faces from his past visits gathered and standing at attention when he kicked off his set with a song dedicated to his grandpa, "They Killed John Henry."

"Memphis in the Rain" led into the first of his many mini-rants and speeches between songs--oratory that is always an adventure at every Earle show. Seeming to take a shot at his introduction's focus on his famous father, Steve Earle, the son dedicated "Mama's Eyes" by calling it "a song I wrote for my mother, because she's the only one who's always been there for me."

He talked of his love for Hank Williams after playing "Ain't Glad I'm Leaving," from his debut 2008 album The Good Life, and after "You Always Look the Other Way," he spun out one of his best lines of the night in introducing "Ain't Waitin'."

"If you can't write a song with just the image of fried chicken and a beautiful woman in your head, you have a problem," Earle stated with a grin. That was just one valuable lesson about life as a musician that Earle taught Saturday, along with the importance of Louis Armstrong in making American music swing, and the fact that country drummers are "the whitest people on Earth."

It's hard to list highlights because the show was a non-stop string of pretty great performances, many of them based in places he's lived during his life, from "One More Night in Brooklyn" to "Halfway to Jackson" to "Harlem River Blues." A cover of Lightnin' Hopkins "The Automobile Blues" was a killer, as was "Maria" and "Your Biscuits Are Big Enough For Me."

Covers of Buck Owens' "Close Up the Honky Tonks" and The Replacements' "Can't Hardly Wait" helped bring the show to a beautiful conclusion, along with his own "Midnight at the Movies" and an encore of "Slippin' and Slidin'."

Would you call Earle's music simply "folk" or "bluegrass"? Probably not. But considering his skills as one of America's premiere young songwriters, he's definitely worthy of the headlining slot he held Saturday night.