Hugh Wheeler for sure (also a strong screenplay writer even his uncredited stuff like helping Cabaret). Was also gonna mention Lapine who is vastly underrated (honestly I think all of Sondheim's collaborators have been good to great, but of course are in his shadow and in some cases definitely did better work with him than anywhere else.). And Hell, I'll add Ashman and Hammersmith (who doesn't get the credit due for virtually inventing the modern musical theatre libretto) there too.
I find Terrence McNally a less and less interesting playwright on his own but I find his musicals books--all adaptations it seems--very strong. ragtime, Man of No Importance, Spider Woman, Full Monty... Ok a few misfires too, but.
I think Joe Masteroff is underrated. She Loves Me arguably improves on its brilliant source material. Cabaret was ostensibly based primarily on I Am a Camera but is much better--better dialogue, focus and the Herr Shultz story was his invention not existing in the stories or play. Also, unlike when Furth revised Company with Sondheim and Goldman revised Follies with Sondheim (two under appreciated books) Masteroff's revisions to Cabaret in 1987--written in a manner of weeks between the revival's pre tour and Broadway opening--honestly strengthen and improve the work.
Updated On: 8/19/16 at 02:03 PM