Dan McGee of Spider Bags. (Jeremy M. Lange/Jeremy M. Lange)

Dan McGee is usually the singer and guitarist for North Carolina trio Spider Bags. But right now, as his band plays for a packed-in crowd at Slim’s in Raleigh, he’s just the singer. He’s offered his guitar to “anyone who can play a G chord,” and a young man up front has volunteered. As the fan strums away, McGee’s chants of “Papa Was a S---head” get louder and wilder, and his bandmates stretch a three-chord stomp into a frenzied mantra.

Moments of spontaneous fun like this are what matter most to McGee. “Rock-and-roll is about immediate connection,” he explains a few hours later, over beer and fries at a diner near Slim’s. “If you write some good songs, people come see you, and suddenly you’re meeting people like you. They don’t need to know my name, and I don’t need to know theirs. We’re all the same, and we understand that right now. That’s what I love about it. That’s why I do it. That’s the only reason.”

McGee’s passion for immediate connection rings loudly in the songs he writes for Spider Bags, who open for fellow North Carolinians Superchunk at the 9:30 Club on Sunday. A rough mix of raucous punk and drunken blues-rock, McGee’s tunes hit the ground running with gruff melodies, twangy chords and punchy rhythms. His lyrics get to the point pretty quickly, too. He spits and drawls hard-luck tales and bar-stool philosophy in a voice that’s confidently direct, yet unafraid to admit flaws. He can sound wry and world-weary, but McGee rarely beats around the bush.

As a result, each Spider Bags song stands sturdily on its own regardless of where it lands on a given album. In fact, McGee has recently steered his songwriting toward singles instead of albums, frustrated with how long it takes to make a full-length one. “Singles are the best way to put out music that represents you right now,” he says. “It’s a thing that you can do that’s contained and sustainable.” He originally intended the songs on Spider Bags’ last proper album, 2012’s “Shake My Head,” to be singles. And their newest album, “Singles,” is a collection of previously released 7-inch tracks that hit with the immediacy McGee craves.

Rock-and-roll itself didn’t come so immediately for the 38-year-old. He began playing in his late 20s, after some years writing fiction. But he has always been into music. He remembers impersonating Elvis the first time he saw him on TV at age 4, and his mother had an even bigger musical impact. “She can sing with anything, so whenever we drove she would sing along with the radio,” he recalls. “A song would come on and I’d say, ‘Mom, sing along with that one!’ ”

Eventually, McGee starting hearing tunes in his head. He claims that he doesn’t sit down and compose pieces so much as he calls on a trove of melodies that have long rattled inside his brain. “I have songs I wrote when I was a kid that are still up there in my mind waiting, and I can tap into them anytime,” he explains. “Sometimes when I do that, it’ll be like, nope, dead end. And sometimes it’ll be like, now is the time to strike!”

McGee’s first strike came in the mid-2000’s, when he lived in Brooklyn and played with indie-punk band DC Snipers. While that group was still together, McGee started Spider Bags and recorded their debut, 2007’s “A Celebration of Hunger,” in North Carolina. During the sessions he met a woman, and he soon moved to North Carolina’s Triangle area of Raleigh-Durham-Chapel Hill to live with her. (His partner in DC Snipers, Mike Sniper, went on to start taste-making label Captured Tracks).

Before his move south, McGee indulged in some hard living, and that’s reflected in “A Celebration of Hunger.” Its songs explore losing money at racetracks, worshipping Kentucky bourbon and how, as one line puts it, “waking up drunk makes me happy.” But he insists his lyrics are never literal confessions. “They come from people I know and situations I’ve been in, but they’re exaggerated,” he says. “It’s about turning those things into something celebratory or comic or tragic. You want people to know that this is a part of you, but it’s not necessarily you.”

McGee is married to the woman he met while making Spider Bags’ debut, and they have a 2-year-old daughter and another child on the way. He’s held a string of day jobs in North Carolina — one involved repairing wheelchairs — and is studying to become an animal chiropractor. “I know it sounds crazy,” he says with a laugh. “But it seems like the only way you can make a decent living now is servicing either humans or animals. Animals seemed like the better way to go.”

Family and career limit the time McGee can devote to Spider Bags, but he insists he’s “not worried about music; I never have been. Playing music is easy.”

His general — and legitimate — disinterest in chasing success frees the band to keep songs unpolished. Guitar fuzz bleeds into screamed choruses; stomping beats devolve into chaos only to storm back. Although McGee bases most of his tunes in 4/4 rock-and-roll, he insists that they get stretched and varied, pushed and pulled. On “Take It Easy Tonite,” a long, horn-filled ending matches the group’s loose, expansive live sets. “I’ve had guys in the band who get upset and say, ‘It’s different every night!’ ” he says. “And I say, ‘Yeah, exactly! Every night is different!’ You want songs that hit the right spots, but you also want them to be alive.”

In other words, McGee likes to keep both his band and his audience guessing — and, in the process, to bring them together. “The whole point is to make a human connection,” he says. “So much stuff is out there to obfuscate your connection to other people. Music can be a way to say, ‘Boom, we’re here, right now. Let’s deal with this.’ ”

Spider Bags opens for Superchunk on Sunday at 9:30 Club. www.930.com.