Evocative of music legends like Sublime and the Buena Vista Social Club, Diego’s Umbrella coined a genre of its own—Mexicali Gypsy Pirate Polka.

As unusual as this self-proclaimed genre may sound, it fittingly describes the unconventional music created by five men who perform weekly in San Francisco and tour the West Coast. Their sound is a mix of everything from surf rock to traditional Latin music and, yes, polka.

While wearing vests and suit jackets, the band members play with intense focus and bliss, losing themselves in a passion for their instruments and the melding of sounds. They transition without losing their audience in a tempo that can switch from a fast-paced jig to a mellow beachside rock in an instant, while fans cheer for their favorite hits or as electric guitarist Tyson Maulhardt “yarrs” his way through a pirate-like remake of Johnny Cash’s “Folsom Prison Blues.”

Maulhardt and flamenco guitarist and vocalist Vaughn Lindstrom, both 29, started the band while attending UC Santa Cruz in the late 90s. According to Maulhardt’s mother, Fredene, she and her husband, John, bought their son a guitar because, “he was a kid with a lot of energy, and he took right to it.”

Since then, Fredene has witnessed an “evolution” in her son’s music and says it’s definitely “more soulful.”

“[Music is] his passion; it makes him happy,” she said.

With high school friend and 2003 SF State business alum Billy Phirman, 29, joining as their bassist, the group moved to San Francisco, where they met their first drummer at Trader Sam’s, a bar in the Richmond district. When Phirman quit to sell carpets, Maulhardt and Lindstrom tried to assemble a full band with musicians they had met in the city.

“There are three important things [when picking a new group member],” said Maulhardt. “You have to get along, musically connect, and share a vision for the future.”

After going through two drummers and one bassist, they found 26-year-old bassist Kevin Blair of Memphis and 23-year-old drummer Reese Bullen of Berkeley. The band’s distinctive sound came into being when Los Angeleno Jason Kleinberg, 36, joined as a violinist and accordionist.

This current line-up is only five or six months old. Alex Gibson, 29, a high school friend of Maulhardt’s, has been listening to the band for about seven years and has heard their sound change.

“They always had an eclectic flavor... It used to be more mainstream, more catchy, more pop surf rock,” he says. “The music now can be for young kids to old 45-year-olds.” In one evening at the Park Chalet, the band’s prime audience went from excited toddlers jumping to drunken adults falling over the amplifiers.

SF State English professor Alex Maurice is a regular at their Tuesday night performances.

“They’re a very eclectic band, they play different music and they come say hello to you. The band has me come here, I would go elsewhere for Taco Tuesday,” he said.

Phil Burnett, 30, is Maulhardt’s house mate, living where the band’s debut album, “Kung Fu Palace,” was recorded. He knew the men when no other band wanted them, and watched as they gained a following.

“They’ve grown as musicians,” said Burnett, a fourth grade teacher who graduated from SF State in 2004 and received his teaching credentials here in 2006.

“They’ve gone in separate ways musically and then brought it together. Vaughn has that Latin flamenco sound and Tyson grew up at the beach so he has that soul sound, maybe Hendrix. They work well together to make a sound that no one else has.”