When Guided By Voices first gained national attention, it did so with an impressive, and in many ways still unmatched, string of albums that combined perfect pop songs with intriguing fragments that could have been. Bandleader Robert Pollard has described his need to write songs as a compulsion, and nothing about his output has illustrated otherwise. That also means quality control hasn't always been a priority, but from 1992's Vampire On Titus through 1995's Alien Lanes, it didn't really seem to matter: A fuzzed-out question mark like "Particular Damaged" (from Propeller) could sound just fine when followed immediately by the anthemic "Metal Mothers." More recent efforts have found Pollard attempting to reduce GBV's unpredictable nature, releasing polished proper-band albums while saving the rough stuff for solo recordings and side projects. If GBV lost some of its enigma and charm in the process, it's a method that last year alone yielded the excellent Do The Collapse and Pollard's best solo album, Speak Kindly Of Your Volunteer Fire Department, a collaboration with Cobra Verde's Doug Gillard. But the compulsion runs even deeper, and the four-disc Suitcase features 100 unreleased tracks dating back as far as 1979. A must only for the hardest of the hardcore Pollard fans, its subtitle—Failed Experiments And Trashed Aircraft—should not be ignored. It takes 17 tracks to hit a song ("Spring Tigers," from the aborted 1992 album Back To Saturn X) that sounds like a regrettable exclusion, and the consistency doesn't pick up from there. Scattered throughout are Who-worthy melodies and amusing rarities (one live track from 1984 captures an inane audience conversation more than the song itself), but you'll have to dig through the ponderous and the repetitive to find them—just like an old GBV album, but infinitely less rewarding. If nothing else, it's a fine warehouse of great song titles (if only a few great songs) and terrific band names, with each track credited to a fictional outfit. But priced prohibitively and generally disappointing, Suitcase songs such as "Ding Dong Daddy (Is Back From The Bank)" by Mooshoo Wharf, "Chain Wallet Bitch" by The Unfriendly, and "Shifting Swift Is A Lift" by Elvis Caligula remain better imagined than heard.