Jason Robert Brown will be appearing with Sondheim at Town Hall in a few weeks--a rare thing, obviously. A couple remarks on JRB: *This guy is most gifted when he is writing about ambition or "hunger." You see that again and again in "The Last Five Years." *For example: The comedy of seeing your friend get knocked up, and pretending to be excited when you're actually, quietly plotting your own escape. "She got a little cute house in a little cute town with a crucifix on the door....Mitchell got work at a record store in the mall....I made Carol Ann a cute baby sweater, thinking, I can do better than that. " *There's comedy, too, in the thought of defying your parents and pursuing the fetish of your choice: "I've had Shabbas dinners on Friday nights...with every Shapiro in Washington Heights....but the minute I first met you, I could barely catch my breath....my Shiksa goddess..." *On the farce of being a struggling actor, in summ...