For more than a decade, etown, taped each week at the Boulder Theater, has been a staple of better National Public Radio affiliates and commercial stations from coast to coast. (In these parts, it's heard Sunday evenings on KGNU, KBCO and KUNC.) The show, hosted by Nick Forster, of Hot Rize fame, and his wife, Helen, combines environmental talk with live performances by many of the nation's finest acoustic and Americana performers. Bluegrass Roots culls excellent samples of the title genre heard by etown listeners over the years, with several cameos by area favorites. Forster pairs with Nickel Creek's Chris Thile for "Woodchopper's Reel," joins Gillian Welch, David Rawlings, David Grisman and Tony Rice on "Train 45," and spends a "Blue Night" with Hot Rize; elsewhere, fellow Hot Rizer Tim O'Brien offers a fast-fingered take on "Hey Joe," assisted by string man extraordinaire Jerry Douglas. Ralph Stanley, Del McCoury, Sam Bush, Ricky Skaggs and others demonstrate their pluck as well, making the disc a first-rate edition to the growing etown catalogue.