Wednesday marked many milestones: the launch of the New York Philharmonic’s 175th anniversary season, Music Director Alan Gilbert’s farewell season, and The New World Initiative — the Philharmonic’s season-long, city-wide project revolving around Dvořák’s New World Symphony and its theme of “home” — plus the Orchestra’s first-ever live concert broadcast on Facebook. The day began with a free dress rehearsal open to the 70+ ensembles performing the New World Symphony across the city as part of The New World Initiative. That night, Mozart in the Jungle cast members Bernadette Peters and Lola Kirke, Josh Groban, Ben Vereen, Hamilton producer Jeffrey Seller, Bill Moyers, Itzhak Perlman, and more were among the friends and supporters who gathered for the Opening Gala cocktail reception, glamorous dinner, and the concert itself — featuring Alan Gilbert leading works tied to the Philharmonic’s rich history of premieres by John Corigliano, Gershwin with Aaron Diehl as soloist, and Dvořák. The Empire State Building shone Philharmonic red in celebration.