After selling millions of records making the “Texican” music that is their bread and butter, Los Lonely Boys decided it was time to expand their sound on their latest disc, “Rockpango.”

They did that by crafting a roots-rock-party record—“Rockpango” is indeed a Spanglish word loosely translated as “rock party”—that, while still retaining Tex-Mex music as its foundation, also draws on such other styles as chamber-folk, straight funk and folk-rock.

The brotherly band—Henry, JoJo and Ringo Garza, on guitar, bass and drums, respectively—comes to the Power Center on Wednesday for an Ann Arbor Summer Festival show.

Also on the bill is the great Alejandro Escovedo, a longtime Texas-roots-rock hero who has been equally celebrated for his blistering punk-rock and complex, innovative chamber pop.

As far as broadening the band’s sound, “It was just time to grow and change,” explains JoJo Garza. “But we didn’t want to change too much. “It’s just progress, maturation and growth. Growing up, being older, seeing the world we’re living in.

“We wanted it to still sound like us. We think our previous records were good ones, but they didn’t sound the way we heard Los Lonely Boys music in our heads,” says Garza during a phone interview from the road. So, the brothers produced it themselves.

“So, this is the way we’ve always heard out music—there’s more of an attack, and the guitar and vocals cut through more,” continues the genial Garza. “It has more of a live sound. We wanted to record songs that were rocking. Even the ballads are more rocking-type ballads.”

On “Rockpango,” the Lonely Boys kick things off with the rocking, infectious “American Idle,” a commentary on the way the recession has affected everyday people. “16 Monkeys” is a goofy but funky song that ‘s heavy on wise-cracking wordplay.

They tapped the Tosca String Quartet to lend chamber-music finery to the melodic “Road To Nowhere” and to the song “Smile,” which is more than a little indebted to the Beatles. And on “Porn Star,” they augment the tune’s Texas-blues grit with a hip-hop flourish at the end.

“Fly Away” is an anthemic rocker, while “Love in My Veins and “Baby Girl” percolate to Latin-style grooves. Meanwhile, the title track and “Change the World” plumb 1960s-style blues-rock as the lyrics engage in some more social commentary.

Along the way, however, the family band had a scare. During the recording sessions, JoJo Garza thought his voice didn’t sound right. So he went to a doctor and discovered that he had lesions on his throat. Obviously, he and his brothers were thrown for a loop.

“Yeah, it was a scare, not just for me, but for the whole family,” says Garza.

Thankfully, the lesions were not cancerous. Garza went in for surgery, then the brothers all laid low in their hometown of San Angelo, Texas, where JoJo recuperated and siblings waited for him to heal.

He eventually did, and when he was back to full strength, they resumed recording.

Garza often speaks openly about his religious beliefs, and says that he gives God credit for the successful outcome of the surgery—which saved his singing voice, after all—and also for everything the band has accomplished, dating back to the 2003 hit single “Heaven,” which ignited their success, and which rose to No. 1 on the adult contemporary charts and No. 16 on the Billboard Hot 100 chart.

“Yeah, we give God credit for everything we get, but we’re not trying to force anyone to believe in anything,” he says.

2003 was also the year of their self-titled debut album, which they released after years of live performing—first as kids, when they backed their father, playing cantinas and honky-tonks, and later as teenagers, when they'd moved to Nashville to try and land a record deal. Then, they returned to Texas, where they continued honing their chops on the club circuit before being signed by Epic.

They followed their debut disc with “Sacred” in 2006, and “Forgiven” in 2008. Then, in ’09, they released a tribute EP, “1969,” featuring 5 covers of songs by some of the acts that most influenced them—the Beatles, Santana, The Doors, Buddy Holly and Tony Joe White. In ‘10 came “Keep On Giving: Acoustic Live!,” which documented their acoustic tour of that year.

But getting back to Garza's health scare and recovery: He notes that “it was really great to see how the whole family pulled together during that time, when I had the surgery and was recovering, and how they gave me so much support. But, really, I think all of us should pull together like that, and should all support each other, as a family of this world.”

Kevin Ransom is a free-lance writer who covers music for AnnArbor.com. He can be reached at KevinRansom10@aol.com