Texas businessman Robert “Beto” O’Rourke, who bested Rep. Silvestre Reyes in last week’s Texas Democratic primary, isn’t just a political rock star. He’s a veteran of the ’90s emo-progressive invasion and has friends that still fill arenas on the reg.

O’Rourke once handled guitar-playing duties for the El Paso-based band Foss (“waterfall” in Icelandic):

“We were all grade school and high school friends,” O’Rourke said of a tightly knit group that once included Grammy Award-winning singer/songwriter Cedric Bixler-Zavala, current folk duo Arlo Klahr and Aisling Cormack (Aisling & Arlo) and buddy Mike Stevens.

Bixler-Zavala continues to perform with the Mars Volta and Big Sir, both of which have new albums out this year. “It was a great time in my life,” O’Rourke told HOH of the band’s short-lived, but surprisingly prolific tenure ­— it released a 7-inch and two full albums in just two years. “I got to tour the country with good friends, meet amazing people and had a really good time.”

O’Rourke brushed aside inquiries about a Foss reunion. But the one-time performer remains plugged in to modern rock.

“I’m listening to all kinds of music,” he said, listing Aisling & Arlo and Sleepercar as “current favorites.”

Assuming O’Rourke carries the day this November, perhaps he’ll request that seminal Foss jams such as “Vendetta,” “The Floor” or “I’m All F*cked Up” be played at the swearing-in.