Pianist Lang Lang joins the New York Philharmonic and its music director Jaap van Zweden for the 2019–20 Fall Gala. Beethoven is the composer of the hour, not least because 2020 is the 250th anniversary of his birth. Lang Lang plays Beethoven’s Piano Concerto No. 2, and then the Philharmonic charges into the master’s Symphony No. 5. —L.J.