Studio recordings of familiar operas are special occasions now, but this one, a vehicle for Dmitri Hvorostovsky as Verdi’s tortured Doge, offers only patchy cause for celebration. The passages in which the velvety authority of Hvorostovsky’s baritone is properly captured are enough to make one wish that he had been surrounded with better support. Only the Fiesco of bass Ildar Abdrazakov, whose singing sometimes puts Hvorostovsky’s drier moments into unflattering relief, is convincingly in his league. Barbara Frittoli’s substantial soprano is at times bluntly used, and she sounds more like Boccanegra’s mother than his daughter. Stefano Secco’s tenor is too slender to capture Adorno’s heroic conviction. Stodgy orchestral playing under conductor Constantine Orbelian doesn’t help: Amelia’s first aria is supposed to be sung over gossamer woodwinds, who touch in the flecks of light as dawn breaks gently over the sea; here it sounds like the sun is being winched up by a crane.