The story of Merrily We Roll Along reaches backward in time to retrace the lives of several people attending a class reunion, and Sondheim's score is typically inventive and complex. Perhaps the clearest explanation is Sondheim's own, as he presents it in the album booklet: "Since Merrily We Roll Along is about friendship, the score concentrates on the friendship of Mary, Frank, and Charlie by having all their songs interconnected through chunks of melody, rhythm, and accompaniment. And since the story moves backwards in time, it presented an opportunity to invent verbal and musical motifs which could be modified over the course of the years, extended and developed, reprised, fragmented, and then presented to the audience in reverse…."

Aside from all this technical experimentation, Sondheim's music and lyrics again demonstrate his cool detachment from his characters, his generally dark and sorrowful view of the unsatisfying messes people can...