Well, wait a Schmig. The formerly dormant trend is active once again with “Schmigadoon!,” the blinding new show at the Nederlander Theatre based on the cancelled Apple TV comedy series about a New Yor...

Even as it slyly acknowledges the reasons for the snickering, the musical “Schmigadoon!” is aimed with laser-like precision at a niche market within a niche market: not just casual fans of Broadway mu...