Jason Isbell didn't work in a sly musical jab by performing his early-career folk gem "The Devil Is My Running Mate." Or trash Roy Moore during his witty, between-song banter. Moore was never once addressed by name or even inference during Isbell's free, solo "get out the vote" concert Saturday night at a packed SideTracks Music Hall in Huntsville. The show was in support of Democrat Doug Jones, Republican Moore's opponent in the U.S. Senate campaign in Alabama which has drawn national attention leading up to Tuesday's election.

Isbell, a Grammy winning singer/songwriter, opened his seven-song acoustic set by saying, "I'm gonna play some songs for you guys and encourage you to please get out and vote for Doug Jones on Tuesday."

At one point onstage, Isbell, a native of Greenhill now residing in the Nashville area, quipped, "I live in Tennessee now so I'm going to need somebody to vote for me. Don't vote for me, I'm not running for office, but vote on my behalf because there's one particular family member that I take pride in cancelling their vote out every time something like this comes up. And I'd like to know I can tell him that again when I see him."

Musically, Isbell was in clear soulful voice. Accompanied only by his Martin guitar, he delivered crisp, campfire versions of recent solo songs. Opening with the big-chords of "Hope the High Road" (perhaps signaling right from the start he'd be taking the high-road and not dissing Moore tonight), Isbell also dug into tunes like "If It Takes a Lifetime" and "Speed Trap Town." "Alabama Pines" and "Outfit," a favorite from his tenure in underground Southern rock band Drive-By Truckers, were the biggest crowd singalongs of the night. He finished off his set with "White Man's World," an electric dirge from his 2017 Grammy-nominated LP "The Nashville Sound" transformed Saturday night with some leafy "Led Zeppelin III"-style flourishes.

Isbell dedicated a buoyant reading of 2015 "Something More Than Free" album's title track to Jones campaign volunteers. "I was talking to a couple of folks in the green room, who said that they had knocked on thousands, literally thousands of doors in North Alabama in the last few days," Isbell said. "And I know from some really difficult experiences trick or treating that that can be a scary proposition. Sometimes you don't want to knock on somebody's door in North Alabama. You get greeted with the sound of a round chambering. Luckily nobody had great aim by the time of night I was giving them trouble so I'm here today. No, you get a warning shot on this side of North Alabama, but Lauderdale Country there's no such thing as a warning shot."

Although Isbell now plays prestigious venues like Colorado's Red Rocks Amphitheater and Nashville's Ryman Auditorium, he clearly hasn't forgotten his time slogging it out in clubs like SideTracks, which has a capacity of around 375 or so. He told Saturday's crowd about numerous gigs he'd played at South Huntsville dive Sports Page Lounge & Deli and the now-shuttered Crossroads (noting he did shows at both the latter-day and original "connected to the mall from the 'Dawn of the Dead'" locations). Isbell recalled a funny episode driving home after playing Mr. C's Lounge, having to dodge a car that had just exited exotic-dancing establishment Jimmy's, going the wrong way. "Luckily he was driving 4 mph on Hwy. 72 so I was able to dodge him."

After several years of seeing Isbell perform on big, shiny stages with his powerful backing band The 400 Unit, it was intriguing to watch him solo in a cramped neon-beer-sign-outfitted bar. SideTracks was only contacted around noon Thursday about the Isbell show.

Saturday night the guitar amps and drums of the venue's previously scheduled headliner, Brother Cane, Thin Lizzy and Alice Cooper guitarist Damon Johnson, were in the background as Isbell played his acoustic set, making him look like some local opening act. That is until Isbell strummed his guitar or sang. Then it was clear why so many fans had waited outside in 32-degree cold, in a long line extending down the commercial center SideTracks is located in, with hopes of seeing a local hero for free. Even though many fans waiting didn't make it inside, a large group stuck around, watching through the venue's windows, grooving and singing along outside. (If there were any Roy Moore supporters actively touting Jones' opponent Saturday here, outside or inside the venue, I didn't see them.)

Clad in a plaid shirt, dark jeans and brown boots, Isbell was poised and relaxed, even as a sound engineer wrestled with feedback and initially applied cover-band levels of reverb to the vocals. Isbell was happy to just play his mini-novels of songs in a stripped-down fashion for a throng of superfans. And do a few jokes too.

"I feel bad because I feel like I should have a harmonica on one of those harmonica holders,' he said at one point. "I think really if you're any kind of a protest singer, if you're playing any kind of a political rally, and you don't have one of those rotisserie harmonica holders around your neck ... but I can't play the harmonica. So just pretend I have one of those so you'll take me more seriously."

Isbell encouraged the SideTrack audience to visit Jones' website, to find voting locations for the high-profile U.S. Senate vote Tuesday. He even kidded that his 18-year-old cousin could give anyone who needed a ride a lift in her Kia to their voting location.

After the last notes of "White Man's World" rang out, the singer bid adieu by simply saying, "I'm Jason Isbell, thank you for listening. Please go out and vote, vote for Doug Jones on Tuesday. Do it, it's the right thing to do." And then he walked off stage.