You know “Andrea Chénier,” but how many other Umberto Giordano operas can you name? Some might remember “Fedora,” or even “Siberia,” thanks to Sonya Yoncheva’s recent performance, but chances are, you might not know that in sum, Giordano composed a total of 13 operas, more than Puccini. But unfortunately, as was the case with a number of other composers of {…}