[5][6] Illyria began as Prospect Theater Company's musical production of Twelfth Night in Central Park in 2001.

[7] The company's artistic director Cara Reichel and resident writer Pete Mills then collaborated to create a complete musical adaptation.

Dressed as Sebastian, Viola finds work as a servant for Orsino, a Duke who is in love with the Countess Olivia.

He is surprised that Olivia is still mourning for her brother (and Feste's former master), and takes it upon himself to bring joy back into the household.

He lightheartedly mocks Maria about her love for Sir Toby, and brings back an old rivalry with the steward Malvolio ("Silly Little Syllogisms").

Meanwhile, the revenge plan is set in motion as Maria writes a “secret admirer” letter to Malvolio, written to seem as though Olivia sent it.

The score of Illyria is contemporary musical theater, drawing in elements of classic Broadway shows and comic light opera.