Original Broadway Cast, 1977 (Atlantic/DRG) (2 / 5) “Wife-swapping” was already a dated topic in 1977, but this miniature musical sex farce was the surprise hit of the season. Audiences were taken with the zippy score by Cy Coleman and Michael Stewart (the latter also wrote the book), and by Gene Saks’ clever staging, which featured four onstage musicians commenting on the action involving two inept pairs of married swingers in Trenton, NJ. The show launched the career of comic actor Lenny Baker, who sadly died a few years later before attaining real stardom. From a 21st century vantage point, many of the songs — with their coy sex jokes and titles like “Love Revolution,” “Sexually Free,” “Ev’rybody Today Is Turning On,” and “Married Couple Seeks Married Couple” — come across as so many outtakes from a PG-13 version of Oh! Calcutta! But Coleman is, as always, a true pro, and Stewart’s lyrics are generally nimble and literate. A few numbers are first-class, including the wistful country ballad “Someone Wonderful I Missed” and the touching title tune. The second-act opener, “Hey There, Good Times,” is classic Coleman — an irresistible ragtime stomp — with delicious Stewart lyrics, though it has virtually nothing to do with the plot of the show. The cast, including the young Joanna Gleason, James Naughton, and Ilene Graff, is fine. — David Barbour