Individually, concerts by the Vienna Philharmonic and piano superstar Lang Lang are among classical music’s most sought-after events. In this thrilling Friday-night performance, they join forces on Carnegie Hall’s grandest stage. Lang Lang is featured in Bartók’s unusually graceful Piano Concerto No. 3, highlighting a gentler, more “classically oriented” side of a composer responsible for some of the 20th century’s most important and demanding piano repertoire. Sounds of nature and echoes of Hungarian folk music carry into the concert’s second half, in which the ensemble—which has often been called “Gustav Mahler’s orchestra”—performs the composer’s First Symphony.