American soprano Deborah Voigt, scheduled to sing Isolde in the season-opening production at Washington National Opera, has withdrawn from the role. The Wagner opera will be performed between the September 15 and 27. Stepping in for Voigt are the Swedish soprano Irene Theorin as well as the British soprano Alwyn Mellor. Voigt made a long summer break this year, partly due to health problems, and now, as she explained in the local press, she is having trouble getting her voice back to where she wants it.