“B.P.M.” usually means beats per minute, but in the case of B.P.M. (1991-1994) it stands for Bridget (Cross), Phil (Krauth), and Mark (Robinson), the former members of Unrest. A suitable subtitle for this collection of arcana—B-sides, remixes, unreleased tracks, “xx” and “xy” versions of the same song, and even a “remix excerpt”—might be “How an Arlington Garage Band Became Almost British.” These 15 tracks find the trio covering a Cath Carroll song; entrusting a radical remix of its song titled “Cath Carroll” to space-rock producer Guy Fixsen (now of Laika); trilling “Hey London!”; and giving a distinctly Anglo pronunciation to “process” (in a cover of James’ “Folklore”). The effect is frequently arch, but—and here’s how British Unrest became —also so jaunty, tuneful, and self-possessed as to seemingly disregard its own pretensions. The disc is available from Teenbeat, P.O. Box 3265, Arlington, VA 22203.