Rosenberg, Marvin. The Masks of Macbeth.
Berkeley: U of California P, 1978.

Thesis: In this massive book (802 pages) Rosenberg attempts nothing less than account of all possible theatrical interpretations of Macbeth. His ultimate aim is to allow his readers to "re-experience the conflicting emotions that simultaneously ravage Macbeth's soul, while at the same time sensing the mask held before his face to hide the inner melee," so that they "begin to know in [their] tissue something of the complexity of Shakespeare's art of characterization" (ix).

Rosenberg calls complexity of characterization "polyphony":

To suggest the many, varied, even contrary strains that . . . actors and critics have found in Shakespearean characters, I will use the word polyphony. I offer this not as a technical musical term, but simply to convey the sense of the many notes in the character designs, and their dynamic, changing patterns. To give a simplified example now: Macbeth knows how wrong it is to murder a guest-king—and Macbeth murders him. Knowing it wrong involves clusters of feeling tones, such as conscience, propriety, civilized manliness. The countering impulse to murder sounds harsher notes, resonant of ambition, cruelty, fear, the bloodthirst of a different order of manliness, practical considerations of committing undetected crime. So intricately designed a characterization can never be perceived as a monody . . . ; sometimes one cluster of notes seems to override all, but even then countering strains may be faintly heard; sometimes the counterpoint swells, and overwhelms the original chords, controlling them, but not extinguishing them.  (x)
For Rosenberg polyphony is of the highest value, and it is the standard by which he judges all performances.

Rosenberg goes through the play scene-by-scene, describing the various ways each scene can be played and the justification for playing it that way. In the course of these discussions, Rosenberg considers what critics have written and also the expectations of audiences at the time of various performances. Throughout, he favors the enactments which avoid monody and express polyphony.

In addition to the chapters on individual scenes, Rosenberg devotes special chapters to the Witches, Macbeth, Lady Macbeth, and Banquo. The chapter on Macbeth (the longest in the book) has, besides an introduction and a conclusion, 15 sections:

For a taste of Rosenberg's method, here's the text of "Macbeth-Lucifer," one of the shortest sections:
     Why are we attracted to splendid evil? Psychologists propose the vicarious delight covertly afforded by surrogate overreachers who perform the wickedness we abjure, who spectacularly but safely let loose the impulses tamped in our own darks. Thus, Macbeth's reckless luxuries of violence, the headlong, wanton plunges into the forbidden that only madness or destruction can redeem. This much purpose in wrong has made Macbeth seem, as noted above, a symbol of, even identical with, the Evil One, Satan—himself a magnificent abstraction of antisocial, antimoral forces in man. But where some critics condemn Macbeth for Satanism, others see an artistic configuration that must earn admiration and empathy.
     For the other side of the devil-villain is the devil-hero. Thus the description of Macready moving from being slave to being hero of wickedness. Let your Macbeth be as magnificent as Lucifer, Mansfield suggested; such Luciferian magnificence in Macbeth, Gardner argued, partly accounts for the sympathy he engenders. The design radiates a splendor of evil (Leech, Sanders), the grandeur of a soul in crime, not the ignominy (Knight), carries immense moral power (Wren); can make even evil seem beautiful, delightful (Croce). So Milton thought of writing his epic about Macbeth, before turning to his glorification of the Prince of Evil. Shakespeare, again, has Malcolm liken Macbeth to the brightest angel. The luminous son would topple the father; the champion turns his arms against Him he should defend; fall he must, but more dazzling in the blaze of his delinquency and defeat than in his subservience—far more dazzling than any pale Galileans who ultimately crush him in enormous pain.
      The fascination, the admiration, the sympathy that the great wrongdoer exerts is frustrating to the moralist who would see Macbeth as an object lesson on the evils of ambition, or hubris, or selfness, or various violations of social and moral codes. Given Macbeth's gigantic stature, the play breathes, as Maeterlinck suggested, in a rarer air than that of good and evil; so Nietzsche argued the futility of dwarfing Shakespeare's concept to a moral sermon on the evil of ambition. Macbeth is too "royal" In his crime:
From the moment he gains "demonic" momentum, he stimulates empathy and emulation in kindred natures. "Demonic" here means in spite of one's own advantage and life, in favour of a relentless thought or drive.
     As Macbeth's destructive, Dionysian energies become endowed with the absoluteness and grandeur that make him kin to Lucifer, he approaches the fine line that distinguishes the heroic villain from the tragic hero.
      The heroic villain, by the vastness of his egotistic vision, by the commitment to it of exceptional body and mind and spirit, suiting hyperbolic language and thought to his action, astonishes, excites and releases in audiences more participation than guilt in his elemental wrongdoing. The design is tempting; Shakespeare exploited it in such characters as Richard III, Iago and Edmund; actors of Macbeth have succumbed, making the character a fascinating virtuoso of villainy. Thus, Irving conveyed so intense and Machiavellian an evil identity that even some critics who resented the desentimentalization yet admired the vision of malign power. But evil, however magnificent, is only one strain in Macbeth's polyphony. It is the more distinctive because so persistently countered by the sometimes diminishing but never extinguished notes of humankindness and philosophical perspective.  (94-95)
As you can see, Rosenberg gives you much to think about.

Evaluation: This is an excellent book, but I would use it as a reference, dipping in from time to time for alternative viewpoints. Reading it from cover to cover (which I did not) would be—I think—overwhelming; fifteen different ways of looking at Macbeth's character is more than I can pull together.

Bottom Line: Smorgasbord Macbeth.