In Sunday’s Post, classical music critic Tim Page asked the question a lot of us are wondering about these days: who will replace Leonard Slatkin at the podium of the National Symphony Orchestra? Slatkin still has two seasons left on his contract, but some rumormongers whisper his name as a possible replacement for Daniel Barenboim, who will be departing the Chicago Symphony Orchestra at the end of this season. If Slatkin does vacate the post,…