richest opera yet written by an American composer", and like Olmstead compares it to Wozzeck and Lulu (as well as to Les Troyens, Moses und Aron, War and Peace, and Palestrina) because, like them, Montezuma has long remained a "legend". Andrew Porter echos the "legendary" characterization and the comparison to Pfitzner's Palestrina, adding that these two operas, as well as Busoni's Doktor Faust, Hindemith's Harmonie der Welt, and Dallapiccola's Ulisse are "both personal and closely argued". At the same time, he cautions that "both text and music are insistent, unrelaxed, and reject passive acceptance", placing unusually high demands on the audience through the combination of Borgese's "Wardour Street diction" and Sessions's musical setting, which frequently superimposes two different vocal settings or accompanies the voices with orchestration that "amounts in performance to stiff competition". Patrick Smith agrees with the comparison to Moses und Aron because both are works "of the mind rather than of the opera stage". However, he does not find Sessions the match of Schoenberg's "ramrod genius", so that Montezuma "remains a tableau-oratorio" in which the salient moments (including a love duet inspired by Verdi's Otello) fail to be "drawn into a cohesive and ongoing whole." He finds the opera's greatest defect is its libretto, a "farrago of poetasty", which is "a ghastly example of self-parody that even a Robert Benchley could not have topped". John Harbison similarly finds parallels between the act-1 endings of both Montezuma and Otello, but also notes similarities to Aida and Tristan und Isolde. He regards the opera highly, describing it as "one of four or five great operas of the century", and this in spite of the fact that, as a "continuous-flow" opera, it is the opposite of the set-piece operas he generally prefers, with clear division between aria and recitative, simple textures, frequent ensembles, and unambiguous dramatic situations and text. As the "best 'way in'" to the music's "monumental force and vivideness", he recommends listening to Sessions's cantata When Lilacs Last in the Dooryard Bloomed (1969) and the Eighth Symphony (1968). Donal Henahan said that the opera lacks, "a dramatically viable libretto and a score worth hearing sung." Peter Maxwell Davies said that the libretto is "full-blown and rhetorical", but "the composer dealt with his text with such assurance that the music convincingly carried even this ponderous weight of language. ... There is little doubt that this is Sessions' masterpiece", and described