Stephen Sondheim’s Sweeney Todd has often been acclaimed his masterpiece, and if ever there was a production to prove it, it’s the 2005 revival. Stripped down in musical arrangement from a fully orchestrated version to a chamber score (with the instruments played primarily by the actors themselves!), the musical reveals itself even more fully as a brilliant mating of words and music. The minimal yet exquisitely scored arrangements highlight Sondheim’s dark drama and black comedy by bringing his noted wordcraft to center stage, while keeping an equally bright spotlight on the nuances and elegance of his expert musical compositions. The celebrated melodious jewels of the work shine as ever -- “The Ballad of Sweeney Todd,” “Pretty Women,” “Not While I’m Around” -- but each song has its delights of attention-grabbing melody and strikingly clever lyrics. The cast, led by Michael Cerveris as Sweeney and Patti LuPone as Mrs. Lovett, is up to the demands of the grand score, relishing the ingenious swings of mood and melody. Reduced in scale but not in vision, this Sweeney is indeed a masterwork.