“ And as Horton, the magnificently sincere Jack Sweeney is close to perfection. Big-hearted and selfless beyond measure, Horton could easily be a drag on the show. But the actor’s hushed concentration and fervent truthfulness are so engaging here that you focus on Sweeney even when he’s tangential to the action, and his vocals are beautifully done; he makes Horton’s “Alone in the Universe” refrain (Seussical’s prettiest piece of music) more moving every time you hear it.
