Pittsburgh Opera’s 2017-18 season is set to keep opera modern with three new works making their way onto the schedule. The season will kick off with “Tosca” starring soprano Leah Crocetto alongside Mark Delavan. That run will start on Oct. 7 and end on the15th. On Nov. 4, “Le Nozze di Figaro” bows with Joélle Harvey, Danielle Pastin and Corrie {…}