After the light-hearted frolicking of Another Midsummer Night, Philadelphia's American Music Theatre Festival continues its 14th season with something completely different: a tragic political opera. Commissioned and developed by AMTF, Black Water uses Greek tragedies -- and the Ted Kennedy Chappaquiddick incident -- as its base as it follows the passionate encounter between a senator and a young woman.

This world premiere features a contemporary, pop-era influenced score by John Duffy. Duffy has written more than 300 symphonic works and has scored such works as Macbird and John Houseman's production of Macbeth.

The libretto is adapted from the Joyce Carol Oates novel by the writer herself. Gordon Edelstein directs the piece, which begins April 24 and opens April 27.

Oates is best known as a novelist (National Book Award winner for them), but in recent years she's become a prolific playwright. Other plays include The Eclipse, In Darkest America, Procedure and Toneclusters. Her I Stand Before You Naked played in February at Hollywood's West Coast Ensemble. Oates co-won the 1990 Heidman Award for One-Act Plays and serves as the Roger S. Berlind Distinguished Professor in the Humanities at Princeton University.

Starring in Black Water will be soprano Karen Burlingame, bass Wilbur Pauley, David Lee Brewer, Stephanie Buckley, Kimberly Graham, Erin Langston, John Savarese, and Tara Venditti. American Music Theatre Festival has staged 66 productions in its 14 seasons, 45 of them world or American premieres. Renovations will soon be underway so the organization can move from its Delancey St. home at the Plays & Players Theatre into the historic Midtown Theatre at 1412 Chestnut St. The former Karlton movie theatre will be renamed The Harold Prince Center for American Music Theatre and include a 450-seat auditorium.

For tickets to Black Water, call UpStages (215) 893-1145.

--By David Lefkowitz