Handel’s oratorio Theodora is an opera in all but name, and this riveting performance led by Russian conductor Maxim Emelyanychev confirms it as one of the composer’s greatest achievements. The American mezzo-soprano Joyce DiDonato is the star name among the soloists, poised and sonorous in her Part I aria “As With Rosy Steps the Morn.” Soprano Lisette Oropesa and countertenor Paul-Antoine Bénos-Djian also excel as the Christian martyrs Theodora and Didymus, rising movingly to the challenge of the opera’s heart-wrenching final scene. The wonderfully eloquent choral singing adds further cachet to a set that lovers of Handel’s music should on no account miss hearing.