- His back-up band will play the first set. This is a good thing. The musicians are always first-rate players, so that first set really gets things hopping.
- Then "The Man" gets a big Las Vegas-style introduction from one of the band members. If you're in a small venue, this comes off a bit weird, but let it slide. A BB King show is not about displaying fierce guitar pyrotechnic flash - it's about enjoying some time with a great entertainer. The man has his own identifiable style, and the genuine warmth of the man comes out even more strongly in a live show.
- At the end, the announcer will shout "B-B-KING" about a dozen times while he takes his bows and throws guitar picks into the audience. If the stage is low enough that he can reach people standing in the front row, he'll shake some hands. (I didn't get a pick, but I did get a handshake!).
- If the audiience goes sufficiently crazy, he'll come back out and do one or two of his early works for an encore.
I don't know what your other plans are, but unless you expect to remember those activities fondly for the rest of your life, I'd recommend the BB King concert. He's not getting any younger. We've lost a lot of great bluesmen recently. He's one of the best we have left.