Author and composer Philip Hall has fashioned an agreeable little musical, and double-threat director and set designer Susanna Frazer and her strong cast of seven men manage to convince us that we are in the prow of such a boat, learning how to pilot it along with Sam Clemens, as Twain was known then, in spite of—or perhaps in part because of—WorkShop Theater’s tiny triangular black-box space. Hall’s songs, in a variety of styles but with most owing an attitudinal debt to sea chanteys, are effective and beautifully sung by the cast, often with the entire septet singing in harmony.