Ricky ChapmanDella MaeBluegrass Concert. Fremont Abbey, 4272 Fremont Ave. N., 701-9270. 8 p.m. $10. All ages. There is quite a lot of pseudo-roots schtick music being made right now that’s been labeled “bluegrass” simply for lack of better terminology. So sometimes, it’s nice to step outside of the indie intelligentsia-approved-band box and check out some artists performing the traditional songs that spawned the best (Whiskeytown, Gillian Welch) and the worst (the Avett Brothers) of the past decade’s formidable roots revival. This show at the Fremont Abbey features artists who specialize in that old-timey stuff: Boston-based Della Mae, Seattle bluegrass band Loose Digits and duo Cahalen Morrison and Eli West. You know, people used to grow bushy beards not out of irony, but because shaving with a strop and a straight razor was a pain in the ass. Do you even know what a strop is? I didn’t think so. SARA BRICKNERPaper Bird, with Lake’ch, Dovekins, Shenandoah. Chop Suey, 1325 E. Madison St., 324-8000. 8 p.m. $8. The banjo is a powerful, powerful thing. In the 21st century, those four or five strings aren’t just limited to bluegrass yarns about the ol’ Appalachian Mountains. Paper Bird have some of that (in this Colorado band’s case, it’s the Rockies), but When the River Took Flight, released July 27th, is more like a joyful, jaunty salmagundi of chiming indie folk, quippy ragtime rhythms and warm vintage pop hymnals, sweetened by three female vocalists, a trombone and, yes, that trusty banjo. MARY PAULINE DIAZBlunt Mechanic, with We Landed on the Moon, Ocean of Algebra. Jewelbox/Rendezvous, 2322 Second Ave., 441-5823. $6. 10 p.m. Definitely playing music you can bone to.