Apollo 18 (1992)

Brooklyn's They Might Be Giants are a Type A band: total overachievers. Apollo 18, the band's fourth album, has 18 full-fledged songs on it, as well as countless unexplored byways of tunes- that-might-have-been. The pop duo — John Linnell on accordion, John Flansburgh on guitar — is attracted to comic-book-inspired topics, which they subsequently inject into their music with dorky charm. On the indelibly catchy song ''Mammal,'' for example, in the midst of jauntily reciting a list of cute animals, singer Flansburgh suddenly informs listeners who may have forgotten Bio 101 that a mammal is a creature ''with red blood cells, lacking nuclei.'' Sometimes the Giants get bogged down in their own cleverness — on ''Fingertips,'' for example, they whip through 22 sound bites without ever settling on a melody. For the most part, however, the band's mad-scientist demeanor and reliance on good old-fashioned tunefulness makes for enjoyable, if terminally lightweight, listening. B+