If you want a hit show, you have to provide an early moment when an audience — content that its hard-earned cash was not spent in vain — is sufficiently impressed that it relaxes, thus opening its collective heart to what is to come, even if that requires a forgiving spirit. Fontana earns that crucial moment for “Tootsie” not just by otherworldly control of the larynx but through stellar, old-fashioned comedic acting, demonstrably rooted in the pain and truth of his out-of-work Michael. By the time he is done, I’ll wager this will go down as a truly great Broadway performance.