Supposedly, there are three things you never talk about in polite company: sex, religion, and politics.

It would seem no one passed that memo on to local "punkgrass" band Haymarket Squares, who formed in 2009 and immediately became a fixture on the downtown arts scene, playing in coffeehouses, bars, and at activist events. Their second album, 2010's Dancing in the Street, explicitly nails at least two of those taboos.

The trio, comprising guitarist and banjo player John Luther Norris, Marc Oxborrow on bass, and Mark Sunman on mandolin, accordion, and guitar (all three members sing), laugh when I share the axiom about screwing, God, and the democratic process with them.

"We need to write more sex songs," Sunman says with a smile.

Other than that one sticking point, the boys have the rest of the ground covered. Songs like "The Rapture" lampoon topics such as the day all Christians will be whisked away, just as all those billboards popping up everywhere seem to be describing — and how much they enjoy the concept. "Bullet Catcher," "Burn It Down," and "Sheriff Joe" all tackle political issues. Along the way, the band makes room for an "anti-fast food jingle" called "Down on the Farm" and a scathing indictment of Phoenix called, appropriately enough, "I Hate This City."

"I like my friends here, we seem to get a lot of shows, we all have good jobs, and property is cheap. There are a lot of things that keep you here, despite the fact that it's a lifeless hellhole that no one should live in, let alone 7 million people who are trying to siphon water from the Colorado River just so they can survive here," Sunman says.

"We could live anywhere and still make fun of it," Norris adds.

"When we play 'I Hate This City' — and we played it all over the West [on tour] — everyone felt like it was about them. Part of it is just universal complaining, which is fun to do as a human. God knows Phoenix is an easy target," Sunman says.

Despite the subject matter, Haymarket Squares are careful how they deliver their diatribes. The band calls what they do "punkgrass," a style that combines the speed and visceral energy of punk rock with acoustic elements of bluegrass. The result is fun to listen to, and it's easy to miss the more aggressive statements beneath the melodies.

It's no accident.

"I think it helps that we package it all in stuff that is pleasing to hear, and a lot of it is in song structure that is traditional," Sunman says. "A lot of it is three chords, and there's a familiarity to it. If the sound of what we were playing was a lot more abrasive, a lot more confrontational, we'd lose a lot more people, but . . . you can enjoy our music as just music."

The Haymarket Squares sing mostly about what pisses them off, but to have a beer with the guys, you would hardly expect it. The three members speak with distinct civility and laid-back charm: Norris, who's originally from Ohio, has an enthusiastic stoner's drawl; Oxborrow, a transplant to the Valley from Michigan, speaks with a measured grace; and Sunman says everything with matter-of-fact plainness.

The band doesn't deny it makes inherently divisive music, but it also don't particularly care.

"Whatever makes you tick is going to come through in your art," Sunman says. "It's easy to do here. It's easy to have that anger, but when there's all this oppression out there, how can it not be reflected in your art?"

"We were interviewed by someone who was like, 'Your songs are so political, and you write anti-war songs,'" Oxborrow says. "Our answer was like, 'I can't believe there aren't more of them!' How come there aren't a thousand songs about this? It's the stuff that is happening all day, every day around us. And yet 95 percent of the songs are about love or getting wasted, or stupid shit."

"We have a song about getting wasted," Norris adds.

"It's not that we're opposed to that, but that's not the only subject matter that is fair game for a pop song," Oxborrow says.

Just as the band explores a variety of topics in their lyrics, they draw inspiration from a variety of sources. Though the Haymarket Squares have a bygone "old-timey" feel, Sunman, Oxborrow, and Norris are far from bluegrass purists. "I don't even to listen to bluegrass," Sunman says.

"The thing that got me into 'punkgrass' was acoustic punk. I started getting into stuff from the Plan-It-X label, like This Bike Is a Pipe Bomb and Defiance, Ohio, and I bought a mandolin and started writing punk songs on that. It sounded 'grassy,' and I just kind of went with it," Sunman says.

The band's sound quickly earned them comparisons to local acoustic rockers Andrew Jackson Jihad, which, Norris says, is "awesome." The band counts the AJJ crew as friends, but isn't quick to lump its music into the same category, though it shares AJJ's freedom of being able to play sans electricity, turning any space into a performance space.

"I'm a fan of pop music," Oxborrow says. "I like songs you can sing along to; I like hooky choruses and harmonies."

When Haymarket Squares toured last year, they realized that the pop-friendly approach allowed them to take their message into some unlikely places. Playing a park in New Mexico, they were surprised to see the reaction of the audience.

"[It] felt like a redneck saloon," Norris says. "All these kids in the crowd and cowboy hats, and we thought some of these songs were going to get us strangled."

But even as the band played "Bullet Catcher," one of the trio's most blunt songs about war, they found the crowd on their side.

"The kids were dancing. They paid for our speeding ticket. They got us this hotel room on the creek," Sunman says. "It was awesome."

The band isn't always as lucky. Sometimes, they can't help pissing folks off, like the time they played an Irish bar in San Francisco.

"Presumably, there were a lot of Catholics in the bar," Sunman says. "We played the song 'The Rapture,' and they didn't take kindly to that kind of song, something making fun of Christians. But we don't care."

The theme of religion comes up often in the band's music, and Sunman and Oxborrow both come from religious households, having grown up in Baptist and Mormon homes, respectively.

"I wrote a song that says I wish there was a God," Oxborrow says. "It would be awesome if there was someone to sort it all out — some cosmic being — but there isn't."

Norris, the group's resident agnostic, didn't grow up religious and admits that the band tries to leave some room for differing opinions, even when their own beliefs are resolute.

"You find yourself with all this pent-up rage toward the system, and there's not a whole lot you can do about it that is effective. But you can make a piece of art about it, and say, 'This is how I feel,'" Sunman says.

"We don't have an agenda. We're a musical group. We're not a political party; we're not a corporation. We're guys who play music for fun. We play music because we enjoy doing it. We're not trying to accomplish anything. We just play what we do, and say what we want to say," Sunman says.

Even if the things they want to say piss you off. Religion, politics — turns out, you can get away with it all, as long as you have a catchy tune.