The jam-band nation has spread itself from coast to coast with dozens of festivals, local gatherings and traveling jamborees. The Spirit of Guthrie Tour adds a new dimension to the scene by focusing on Woody Guthrie's recently discovered writings. A Herculean stable of songwriters--headed by Leftover Salmon's Vince Herman and including modern-day bass legend Rob Wasserman of Ratdog, free lyrical wordsmith Jim Page, and newbie Theresa Andersson from the tour's foundation--take to the stage with solo sets and group improvisations on Guthrie's work. Catch it Wednesday, March 30, 10 p.m. at The Pour House. Tickets are $10; 821-1120 or www.the-pour-house.com.