A young man and the girl next door have parents who have built a wall to keep them apart. The youngsters nevertheless contrive to meet and fall in love. Their parents, meanwhile, are congratulating themselves, for they have erected the wall and staged a feud in order to achieve, by negation, a marriage between their willfully disobedient children. Altogether, it’s a rueful and disarming lighter-than-air romantic musical fantasy. As the longest running musical on the American stage, it comes back to ACT’s stage after 12 years by popular demand. You’ll hum, you’ll whistle, you’ll hardly ever get out of your head such songs as “Try to Remember,” “They Were You: and “Soon It’s Gonna Rain”