The Essentialisn’t is the most awkward title of the theater season so far, but never mind that. Eisa Davis’s intimate musical enfolds its spectators in the cultural recollection of the earliest Africans brought to this country and in Davis’s own search for identity through music, acting, and dance. It’s an ambitious undertaking focused on what Davis calls “personal sovereignty.” Davis, who is billed as creator, performer, and director, poses a multivalent question—“Can you be Black and not perform”—which appears in bright fuchsia neon onstage throughout the play.