For the past year, Jeff Harlan has been banging on the door of the RFT on a weekly basis, diligently and politely offering us news on his upcoming shows, shows that, unfortunately, few of the paper's critics care much about. These days, the jam-band circuit is flooded with imitators, and it's tough to weed through the bad and get to the good, especially if the good among them doesn't even yank our chain. But he keeps plugging away politely when others in similar situations are calling us names, damning us to hell and carelessly burning their bridges.When you peek beneath the surface of Harlan's bookings (you can tell them by the JHP logo, one that replicates the STP-gasoline-additive logo), though, you can see not just the "jam bands" (an amorphous tag that usually means nothing) but a love of traditional American music that ranges from bluegrass, folk and country to blues and jazz. On even further examination, it becomes apparent that Harlan doesn't actually book that many jam bands per se but books acts that draw on the myriad influences without falling into the trap of simply sounding like the Grateful Dead. Jeff Harlan Productions celebrates its one-year anniversary this week by bringing two acts that perfectly illustrate his tastes. The Blueground Undergrass bill themselves as a "progressive American roots music" band and roam a territory that includes bluegrass, country and basic roots music. The Yonder Mountain String Band is a more traditional outfit that draws on the classic string-band tradition of Mississippi and Louisiana but stretches it a bit further. They'll move from a foggy-notion breakdown to a '60s-style Bakersfield ballad without skipping a beat, and the result is often beautiful.