Sennet sounded. Enter Macbeth as King, Lady [as Queen], Lennox, Ross, Lords, and attendants

MACBETH      Here’s our chief guest.

LADY              If he had been forgotten,

It had been as a gap in our great feast,

And all-thing unbecoming.

MACBETH     [to Banquo] Tonight we hold a solemn supper, sir,

And I’ll request your presence.

BANQUO        Let your highness

Command upon me, to the which my duties

Are with a most indissoluble tie

For ever knit.             (3.1.11-18)

This is it, Macbeth’s made it (and Lady Macbeth has too). Perhaps there’s some visual continuity with Duncan’s earlier appearance: a royal robe, a crown. The trumpet fanfare, the sennet is a contrast to the alarums, the battlefield trumpet calls to which Macbeth has hitherto been more accustomed; in  performance there’s sometimes a suggestion that they’ve come straight from the coronation ceremony itself. As many people are there as is possible, Lords, and attendants; Banquo might look quite isolated, and Macbeth’s greeting—Here’s our chief guest—while quite jocular, could have a bit of an edge to it. So this is where you’ve got to. What are you doing out here, on your own? Lady Macbeth smooths it over: if he had been forgotten, it had been as a gap in our great feast, and all-thing unbecoming. We couldn’t have a party without Banquo! He’s essential to our celebrations! (The gap in our great feast looks forward to what’s actually going to happen at this dinner party: the empty stool, the palpable absence.) So Macbeth reiterates the invitation, in a way that’s easily played as slightly self-mocking in its formality—tonight we hold a solemn supper, sir: look at me, King! issuing invitations; is wethe two of them, the Macbeths, husband and wife, or is it the royal plural? It can be both, I think, with the switch from we to I—and I’ll request your presence—suggesting that this invitation isn’t coming from the monarch, but from me, your old mate Macbeth. Come to dinner, old friend! Banquo’s going for formality, though (although this too could be slightly ironic; look at the crazy situation a couple of old soldiers have found themselves in!) Let your highness command upon me, to the which my duties are with a most indissoluble tied for ever knit.Your wish is my command; I live to serve; I am bound to you forever, in duty and service. An uneasy little exchange, all these platitudes, landing just slightly off, the sense of a bond of trust and understanding broken, or at least under very great strain. Watchful, on both sides.