You know we’ve reached the lower depths of summer when all the theatre-world wags in New York can find to talk about is the first preview of Sondheim’s “Into the Woods,” a free Public Theatre production in Central Park which stars Amy Adams. The New York Post’s Michael Riedel is leading the naysayers. The thing that most pains me (if it’s true) about the problems with the first previews, held this week, is the lack of musicianship. La Riedel reports: “The Public Theater…hasn’t installed a video monitor on which the cast can watch the conductor. As a result, during those tricky Sondheim ensemble numbers — “First Midnight,” “Ever After” — the actors were coming in all over the place.” Yikes.