Even if you’re not a soul music fan, a devotee of big, flashy Broadway musicals or an admirer of playwright Dominique Morisseau—who wrote not only the musical hit about the Temptations, “Ain’t Too Proud,” but also such dramas as “Skeleton Crew” and “Paradise Blue”—and even if you have no nostalgic feelings about the decades-long TV show “Soul Train,” there’s much to admire in “Hippest Trip: The Soul Train Musical,” a bound-for-Broadway world premiere now at American Conservatory Theater.
