Much like the three volumes before it, the fourth annual commemorative disc of the International Pop Overthrow festival contains a mixture of hits, album cuts, and rarities from some (though not all) of the bands that appeared at the festival. And like its predecessors, the fourth installment in the series is a bit uneven. But also like Vol. 3, it contains some very immediate guitar-based pop music from some of the most talented and underappreciated power pop groups in 2001. The biggest gems here are, of course, the unreleased tracks from more familiar names: Brendan Benson's "Folk Singer" appeared here months before official release; Swirl 360 contributes "Lost You," their first new track since their debut; and the Andersons include the hard-rocking "Listening Station," a song not included on either of their first two albums. More highlights come courtesy of the Masticators' "This Time Right Now," a slice of gooey girl group pop; the Davenports' smirking piano pop ditty "Hi-Tech Lowlife"; and the Scooters' new "Do Whatever." And the previously released album tracks from the likes of Einstein's Sister, Cliff Hillis, and Sparkle Jets U.K. are examples of some of the best power pop offerings of the year. But the highlight on the sprawling, two-disc set is "Boycott," an anthemic, brand new Raspberries-influenced rocker from the Mood Elevator. There is, of course, a lot of filler in between, but the best moments on this compilation are bound to make listeners seek out the actual albums, and the previously unissued material is necessary for fans.