Wells, Stanley. "A Scottish Tragedy: Macbeth."
Shakespeare: A Dramatic Life. London: Sinclair-Stevenson, 1994. 282-299.

Thesis: Wells' chapter on Macbeth could serve well as a general introduction for the novice reader. He sees the play as both a "sheerly exciting . . . fast-moving murder story" (282) and as "profoundly moral," but not "moralistic" (299). He writes well about both of these characteristics of the play and also provides a lot of readable commentary about character development and theme. For a sample, here is part of his commentary on the theme of equivocation:

The overt expression of the witches' equivocal nature comes in the set of prophecies delivered by the apparitions in the cauldron scene (4.1). In spite of Banquo's warning, Macbeth continues to place his trust in the weird sisters; he accepts their oracular statements at face value; these prophecies do indeed seem fair, it does seem impossible that Birnam Wood will come to Dunsinane, and there seems no reason why Macbeth should not feel confident after he is told that 'none of woman born | Shall harm Macbeth'. But after all, the first apparition has warned him against Macduff: 'beware Macduff, | Beware the thane of Fife', and it is at his own risk that he, who has been so apt to create a false impression, should take their other statements at face value. It is Macbeth's powers of self-deception that bring about his final overthrow. The ambiguous nature of the witches symbolizes the power of choice that he is given, and in the play's last minutes we have a vivid visual symbol of the destructive force of his self-deception when the army led by Malcolm and Macduff adopts the device of carrying the branches of trees as camouflage, so that it seems as if Birnam Wood really did move towards Dunsinane. The tables turned; Macbeth's bloody instructions return to plague the inventor; the fair appearances of evil are foul at heart.  (292-293)
Also, Wells occasionally spices his writing with a bit of humor, such as this: "Caithness, Mentieth, Lennox, Ross, Angus -- they sound like extracts from a tour guide to the Highlands, and have no more individuality than decreasingly important railway stations along a minor branch line" (288).

Bottom Line: Very good.