WITH the arrival of Alan Gilbert as the music director of the New York Philharmonic in 2009 came the promise of youthful vigor and bold initiatives. But who could have anticipated that by the midpoint of Mr. Gilbert’s second season the Philharmonic would be a potent, even groundbreaking force for contemporary music? The most striking example of Mr. Gilbert’s expansive view of the Philharmonic’s potential  and the greatest triumph achieved by any New York musical institution in 2010  came in May, when the orchestra presented the New York premiere of Gyorgy Ligeti’s opera “Le Grand Macabre”

It was no revelation that the Philharmonic could tackle opera; shortly before Mr. Gilbert had arrived, Lorin Maazel conducted creditable concert accounts of Puccini’s “Tosca” and Strauss’s “Elektra.” But Ligeti’s opera marked new territory, both as an extravagantly challenging composition that demands much of its performers and as a 20th-century milestone that New York’s full-time opera companies had neglected to address. Seizing the opportunity Mr. Gilbert and his colleagues assembled a brilliant cast; devised a lavish, innovative production directed by Douglas Fitch; and mounted an inventive media campaign that helped to attract sold-out houses.