It was six years ago, at the substantial age of 80, that Riley “Blues Boy” King announced to the world that he was launching his farewell tour. Of course, even then, we knew he didn’t mean it, and he did too, acknowledging with a wink that he wasn’t going to stop playing or singing classic electric blues as long as he was above ground. Now, King is knocking on the door of 90, and he still hasn’t said a final farewell. Age has changed his powerful voice, but he’s still an amazing guitar player, and playing with just about every decent blues musician of the last seven decades has taught him more about showmanship than most performers will live long enough to learn. King won his 15th Grammy as recently as 2008 (for the risky, raw-sounding One Kind Favor album), and he’s enhanced his already strong live presence with a newfound interest in the early roots of his art form. He’s also, unsurprisingly, a terrific storyteller between songs. No one lives forever, and time will eventually catch up to the greatest living bluesman. Until it does, King — the very definition of a living legend — will be worth seeing. $60-$75, 7pm Sun, Aug 19, Majestic Theatre, 224 E Houston, (210) 226-3333, majesticempire.com. Check out our full online calendar of upcoming events here: calendar.sacurrent.com.