There was a time when reviewers excited about an opening would resort to the “Run, don’t walk…” plug. You don’t hear it much nowadays. Nonetheless, I’m reviving it for Harmony, the superb new musical for which Barry Manilow wrote the tunes and Bruce Sussman wrote the lyrics and book. Be advised not even to run but to race to this tale of a six-man Berlin singing group that was founded in 1927, became an international sensation by the early 1930s, and disbanded when Hitler decided that the three Jewish members must no longer appear on stage but were better off leaving the country, as they were able to do. Sounds like a grim story, and it is. But not completely so, as the title suggests and as its authors hope in an implied message that remains as cogent today, when antisemitism in on the rise domestically and globally. Whether that wished-for goal is attainable or not, Manilow, Sussman and crew are ebulliently pushing for harmony musically and societally.