The liner notes to the latest CD from Austin’s Asylum Street Spankers, Spanker Madness (Spanks-a-Lot), list a whip, a backhoe, and “various pieces of metal piled in the back of Leroy’s ’67 Ford F100 parked in the studio driveway” among the instruments. And the music, which invokes and tweaks vaudeville, country and western, acoustic blues, and western swing, is a cowboy-hippie tokefest the likes of which haven’t been heard since the New Riders of the Purple Sage galloped off into the sunset with their good friend Panama Red. But despite the gonzo posturing, the musicians’ dedication to their craft is thorough–in homage to Depression-era buskers, they refuse to use amplifiers–and their chops are formidable. Though vocalist-harpist Wammo affects a ludicrous trailer-trash drawl on “Beer,” running through a list of drugs he isn’t currently doing (“Marijuana makes me wanna / Eat candy and eat Madonna”) before settling on you-know-what, his harmonica work dexterously mixes and matches riffs borrowed from blues pioneers like John Lee “Sonny Boy” Williamson. On “High as You Can Be,” Christina Marrs turns in a spot-on impersonation of a 1930s blues singer: her intonation and timbre make her sound both streetwise and sexy, and her lyrics are time-warp authentic (“You’s a lazy old viper / You ’bout to make your mama mad”). And on “Winning the War on Drugs,” a rollicking breakdown to the tune of “Ghost Riders in the Sky,” Korey Simeone’s searing double-stopped fiddle lends a sense of urgency to the tomfoolery; the tune’s social commentary may not sound too serious (“They’re makin’ money off the stash / And money off the jail…Put yer hands against the car / We’re winning the war on drugs”), but the Spankers stand behind every punch line. Only occasionally does the shtick overwhelm the music: the aimless “Amsterdam,” for instance, really does sound as if it were recorded stoned. For these dates, founding members Marrs and Wammo ought to show up, but it’s anybody’s guess who else will be there: in seven years the band has had around three dozen members, and it tends to tour with a crowd. Friday, May 25, 10 PM, the Hideout, 1354 W. Wabansia; 773-227-4433. Sunday, May 27, 7:30 PM, Schubas, 3159 N. Southport; 773-525-2508.