311 talks being the odd band out on the metal-heavy Carolina Rebellion bill

For a band accustomed to marathon five-hour sets like the ones 311 plays every other March 11 for diehard fans, a festival date is like a snack.

“We just got done doing the Guitar Center Sessions, which is eight songs,” says 311 bassist Aaron Wills (aka P-Nut). “It was a total walk in the park. It’s the same thing for festival shows, which are an hour to 85 minutes. It’s easy to let it all go by and wow, there’s only three songs left. We can just deliver endlessly as hard as we can.”

The surfy California-by-way-of-Nebraska group – which has mixed reggae, hip-hop and funk with hard rock for a quarter of a century – will certainly stick out in the metal-leaning Carolina Rebellion Festival, which takes place Saturday and Sunday.

311 headlines Sunday with Kid Rock and Five Finger Death Punch, while Avenged Sevenfold and Rob Zombie head up Saturday’s 15-band bill.

“It’ll be a challenge for us,” Wills says. “Approaching 25 years as a band, to still be able to have challenges and want to face them is a great thing. We’re excited about these shows. The Charlotte metalfest stands out because of how our loyal flag-bearing fans were like ‘Cancel that show!’ It was weird. The faithful were shook for some reason.”

It’s not as if 311 can’t rock. Its new album, “Stereolithic,” is full of the crunchy signature guitar hooks that made them famous, along with the laid-back sing/rap delivery. Wills thinks it’s the band’s best album in years.

“We’d been making some good music and making some good songs, but we hadn’t put out a damn good album for the last 10 years,” he says, crediting producer Scotch Ralston with helping refine the direction.

“Stereolithic” is by far 311’s most collaborative album, with Wills contributing lyrics with songwriters Nick Hexum and SA Martinez.

“When we collaborate, there’s something about it that goes along with the whole mixing up of styles and the dance with harmonies and hybrids,” Wills says. “It makes a little more sense. Writing lyrics, there was way more of a committee with me, Scotch, Nick and SA. Seven songs we wrote together.”

That gives Wills a deeper connection to the songs.

“It started with ‘Sunset in July’ on the last album and how fun that was to see people saying some of my words,” he says. “Nick and I worked on the chorus together. More than anything, I’m just pushing him and SA into the directions they want to go and maybe making them cancel out things that wouldn’t be top shelf.

“I have to think in their headspace. I’m not a vocalist, nor would anyone want me to be besides maybe my mom. I have to put on their thinking caps as well as bringing new stuff to the table. A lot of times I’m blurting out ideas. Those can turn into lyrics that people will remember and learn.”

He thinks he’s found a new niche.

“I love to collaborate, but it’s been ... frustrating trying to write music that makes it through the filter to get to the album for me,” says Wills of finding a home for a “square peg of an idea.”

“It can be hard to make it fit. Lyrics and words and philosophies and emotions I can do with my eyes closed. I think I was made for this. It just took a while for them to let me in.”