The Philharmonic, with guest conductor Case Scaglione, and soloists Suzanne Vinnik, a soprano, and tenor Cody Austin, opened its season on Saturday with a program titled “Operatic Love.” While the two singers, especially Vinnik, drew the lion’s share of audience attention, the star of the night was the orchestra. Of four strictly instrumental works two were, shall we say, ordinary; the others were truly exceptional.