The Rural Grit "booze collective," as one regular puts it, has been staking out bars for several years. (It was the last troupe to perform onstage at the Grand Emporium before that club's transformation.) But the mountain-music, open-jam tradition it maintains is as old as America. Founded by Ike Sheldon (Brother Ike of the Wilders) and named for his band's record label, Rural Grit now takes over the Brick from 6 to 9 p.m. on Mondays. The darling old honky-tonkers of Checkered Past bring acoustic sass to the stage between open-mike sets from fresh-faced kiddos and eccentrics alike, such as big-bearded Mark Smeltzer, who makes instruments out of frying pans and other household objects. The gritsters take care of one another, too -- 10 percent of every Rural Grit CD sold goes into a health fund to aid musicians who can't afford private insurance. Now that's something to holler about.