JONI MITCHELL and the Joni Jam - I gave it some thought. RECOMMENDED, or HIGHLY? After all, her immediately identifiable soul-stirring high tones have dropped a bit over the years, and as a performer, she's nothing like her former pre-stroke self. She deserves all praise and admiration for having so courageously fought back to learn to talk and sing and even play guitar again, but would you pay $1,600 for standing room right next to the stage? When she won't be the one performing for most of the concert? I guess the answer is a resounding yes because this year's Joni Jam is booked for two nights at the Bowl. Her friend and benefactor Brandi Carlisle will be handling most of the music direction role, but she is an outstanding performer in her own right. And she promises this one will be "even crazier" than previous ones. Let's be real: it's Joni Mitchell and there's never been anyone like her and we will all be the poorer when she is gone. So go and catch a glimpse, get a listen, and you may well remember it the rest of your life. After all, few of us have the memory of having gone on a dinner date with her. Sat 7 p.m., Sun 6:30 p.m., Hollywood Bowl, $57-2,668.