Chuck Mead and his Grassy Knoll brought their rockabilly- Western swing to Jammin’ Java in Vienna, Va. (Marlon Correa/The Washington Post)

With a conspiracy theory-mocking moniker like Grassy Knoll Boys, you know frontman Chuck Mead isn’t playing things completely straight. And there was plenty of good-natured hillbilly ironizing at the Nashville-based quartet’s appearance Sunday night at Jammin’ Java in Vienna.

But over a blistering 90-minute set, you’d have been hard-pressed to hear anything but deeply felt affection for and fealty toward classic country, Western swing and rockabilly.

Formerly of the cult heroes BR549, Mead offered an infectious mix of covers of songs made famous by the likes of Del Reeves, Carl Perkins and Johnny Horton, plus originals written in the spirit of same. Mead’s rocker “She Got the Ring,” for instance, was almost certainly a lyrical nod to Jerry Reed’s hit “She Got the Goldmine (I Got the Shaft).”

Mead’s mastery of the grammar of country guitar, its vintage twang and reverb and greasy licks, would have been even more impressive if he hadn’t been performing next to Carco Clave, the staid elder statesman to Mead’s straw-hatted hambone. Seated most of the evening at a pedal-steel guitar, but occasionally strapping on an electric mandolin or a banjo, Clave’s long and speedy musical phrases seemed to defy the physics of steel strings and human fingers.

While there were laughs to be had at the druggy blue humor of songs like “Scattered All Over the South” and “Me ’n’ Opie (Down By the Duck Pond),” there were subtle hints of social conscience in the poignant ballad of a depressed small town, “Up on Edge Hill.” And there’s no faking the emotion of Hank Williams Sr.’s “There’ll Be No Teardrops Tonight” or Webb Pierce’s “There Stands the Glass” or the Tammy Wynette classic “Apartment #9.”

Mead may have joked about the way that he and his bandmates play country, but there was no mistaking the reality beneath the spirited surface. Mead and his Grassy Knoll Boys are highly skilled, and deadly serious.

Galupo is a freelance writer.