Gaetano Donizetti wrote 65 operas. The average operagoer might be able to name five or 10 of them. They are not performed often; some of them, hardly ever. They are creations of a specific place and time, written to show off star singers and please audiences. They are also extremely difficult to sing. But in Washington last weekend, you could see two of them -- "Lucrezia Borgia" at the Washington National Opera on Friday, with the soprano Sondra Radvanovsky making a triumphant company debut in the title role, and "Maria Padilla" at the Washington ... (more)