The heroine of the 1965 original musical is “Daisy Gamble, who discovers with the help of [a] psychiatrist … that she was, in a past life, Melinda Wells, a woman who lived in 18th-century Britain.” The new version, starring Harry Connick Jr. and opening this fall, turns Daisy Gamble into David Gamble and Melinda Wells into a 1940s jazz singer.