Soldiers of U.S. Army Europe’s 170th Infantry Brigade Combat Team will march through Moscow’s Red Square in Russia’s 65th Victory Day parade on May 9. The event marks the first time a serving, active-duty U.S. Army unit, carrying the American flag and representing the United States, will march in the parade.   What does this have to do with music? It’s not that kind of parade. But it did remind me of the efforts of Serge Koussevitzky  on behalf of our “Russian Ally” during World War II.   When I first found this postcard in the Lenox Library’s Tanglewood Papers, I remember being struck by the reminder that we were not always Russia’s enemy.