Don't go to Black Barts for a gourmet dining experience but to have fun enjoying lots of live music, show tunes, and humor (not a highly-polished show but spontaneous and spirited).
I'd suggest ordering one of the less spendy dinners--you're going to be too distracted by the show to sufficiently savor a $30 ribeye steak even if it WAS perfectly executed. If you're not in a relaxed, ready-to-have-fun-whooping-it-up-with-the-crowd mood, then you might be doing everyone a favor by going elsewhere. I went in a party of 8 including 4 little kids and we had a TERRIFIC time. After a musical number from The Littlest Mermaid, one of our little kids said, "I liked that so much I'm crying with joy!" There was A LOT of surprise, laughter, and roaring with delight by many of the dinner guests.
They waived the normally-mandantory 18% tip for parties of 6 or more so I tipped them even more than that. What with all of their performing on top of attentively meeting our needs, the wait staff worked three times as hard as at most restaurants.