Released in a limited edition to coincide with the irregular festival of the same name -- its sixth installation was held in Providence, RI, also the site of the first festival nearly ten years previous -- Terrastock Six is a fine souvenir featuring 11 of the many bands who performed. Beginning with "Radio Carpathians" from Poland's Magic Carpathian Band, a snippet of broadcasting leading into a huge guitar riff courtesy of commanding vocalist Anna Nacher, Terrastock Six wisely covers the range of what the festivals have regularly offered, from mind-melting ultra zoned-and-stoned creations to gentle, fragile compositions. As has always been the case with the original parent publication Ptolemaic Terrascope, psychedelia is here less a freeze-dried style than a signpost for a significant possible range. The bookending entries on the compilation sprawl -- the Magic Carpathians for almost 12 minutes, Bardo Pond's striking cover of David Crosby's "What Are Their Names" for nearly 13 -- with the remaining tracks filling out the disc in generally shorter fashion. A one-off collaboration between Black Forest/Black Sea, who helped put on the festival and released the compilation through the Secret Eye label, and the theatrical, dramatic Larkin Grimm results in "On the Cliffs at Fort Wetherill," an at times unnerving blend of calm contemplation and creepy sonics, while Grimm's singing slowly emerges out of the mix. Finland provides a double dose via the interrelated bands Kemialliset Ystävät ("Paha," a short collage of drones, wordless vocals, keyboard parts, and what sounds like a not-very-calm cat) and Avarus ("Himopanija Rokkihieronnassa," with low feedback howls set against spiraling trebly riffs). Some other stand-out pieces include the P.G. Six's "Outtake #1 from the Sherman Box Series," a slow, entrancing composition on what sounds like autoharp, and the Spacious Mind and Kinski's explorations of their minimal/dark impulses, feeling like the aftermath of huge explosions.