Where in the world is Illyria? It's such a pretty name it seems Shakespeare must have invented it.

Which, in a sense, he did, reviving a name out of Roman antiquity and occasional later usage. This historic-legendary status is perfect for the location of one of the Bard's archetypal comedies where the heroine, Viola, is shipwrecked on an unknown stretch of the Balkan coast, dresses as a man for safety, stumbles into a local story of confused loves and drunken revels and ... well, you know the rest.

What you don't know, or at least I didn't, is that the resulting comedy, "Twelfth Night, or, What You Will" (note the covert pun on the author's name, which is not the Earl of Oxford), has been the basis of a half-dozen musicals. The most recent are "Play On!" and "All Shook Up," using the music of Duke Ellington and Elvis, respectively, and "Illyria" (2002), with book, music and lyrics by Peter Mills, co-adapted by Cara Reichel.

"Illyria" is now having its local premiere at the Pittsburgh Playhouse, nicely realized by the Point Park University conservatory students. It well justifies the considerable skills involved, but it runs just through this weekend, so hurry up if you want to add it to your lifelong list of Shakespearean musicals alongside its more famous kin, such as "Kiss Me, Kate," "West Side Story" and "The Boys From Syracuse."

"Illyria" doesn't rank with those, but it has plenty of pleasures, starting with Shakespeare's story of twins separated in that shipwreck -- one male, one female, to multiply erotic confusion. Mr. Mills slims down the dramatic personae and plot and uses Feste, one of Shakespeare's more enigmatic jesters, as a narrator to make the story clear. He then lets it spiral up into follies more extreme than in Shakespeare, my favorite being that when Orsino discovers he's in love with his young male friend (not realizing yet that she's a girl), he proposes to him anyway.

Mr. Mills actually improves on Shakespeare one way, having the disguised Viola take the name of her twin, Sebastian, whom she assumes is dead, adding another fillip to the inevitable confusion. He also adds to Shakespeare's store of word play -- I especially like some of his rhymes (iamb/I am, imbroglio/Malvolio).

The main loss is that the bewildering danger of Shakespeare's play -- one of his more complex, mature comedies -- is softened. But after all, it's an American musical comedy, emphasis on comedy.

The score isn't instantly memorable, but it is almost invariably pleasant, and it has a couple of numbers that make me want to find the CD, especially the lively, comic "Cakes and Ale." Both the score and the show itself get better as they go along.

More memorable than the score is the scenic design by Gianni Downs, which rises to a concept with its Magritte-like forced perspective, forest of lights and dancing massed umbrellas, all perfectly adapted to the bewilderment love and alcohol create. Andy Ostrowski's lights and Michael Montgomery's costumes thicken the visual enchantment.

The student cast is appealing, especially Ryan Novakovich (Orsino), Jaclyn McSpadden (Olivia) and Amy Van Norstrand (Maria). Paul Koudouris (Malvolio) is physically inventive, and Connor Russell makes Sir Andrew foolish in an unusually plausible way.

The knitting of design, music (Camille Villapando Rolla, director) and dance (Jeremy Czarniak, choreographer) is accomplished by the very capable direction of Scott Wise.

One test of an adaptation is to send you back to the original. Point Park makes that easy, because it will stage the real "Twelfth Night" on the same Rauh Theater stage and I think using even the same set, Dec. 9-18.

First Published: November 16, 2011, 10:00 a.m.