Opera music lovers should go today to purchase their tickets at the National Theater for an extraordinary evening listening to Francisco Casanova, the Dominican who has substituted for Pavarotti and performed at the Carnegie Hall of New York City. He will be the star of a gala concert to commemorate the 74th anniversary of Club Libanés-Sirio-Palestino at the National Theater. The event is a fund-raiser for the construction of the clubhouse of the organization that groups Dominicans of Arabian-descent. Maestro Caonex Peguero Camilo directs the program. Casanova will sing arias of his traditional repertoire, "Recondita Armonia" of Puccini, "O Paradiso" from L’Africana, "Questa o Quella" and "Di quella pira" by Verdi, and "Siboney" by Lecuona in a special arrangement by Maestro Peguero Camilo.