Based on the classic Hans Christian Andersen fairy tale, and the wildly popular Disney film, this musical staging of The Little Mermaid features a funny and fanciful book by Doug Wright, with the beloved score by Alan Menken, Howard Ashman, and Glenn Slater in an expanded but completely faithful form, featuring the rambunctious and persuasive “Under the Sea,” the romantic expectation of “Kiss the Girl,” and that anthem to longing and belonging, “Part of Your World.”