For a long time, Stephen Sondheim"s 1974 compact offering The Frogs was known for two things. It was originally staged in Yale"s swimming pool with a chorus that included Sigourney Weaver and Meryl Streep and its song "Invocation and Instructions to the Audience" has become a perennial in Sondheim tributes and cabaret shows. The show was given a belated studio recording in 2001 with Nathan Lane in the lead role of Dionysus. Lane then went back for more--literally, since he adapted and expanded Burt Shevelove"s book--and Sondheim wrote several new songs. Finally, The Frogs was a full-length musical, staged in 2004. New tracks "I Love to Travel" and "Ariadne" are on par with Sondheim"s best--the first a bouncy song, the latter a wrenching love song that could become a new recital favorite. While this recording is more enjoyable than the actual show, which could be a bit of a slog, it"s hard to shake the feeling that maybe The Frogs should have remained a curio.--Elisabeth Vincentelli