Marin Alsop kicks off her four-season appointment as Principal Guest Conductor of London’s Philharmonia Orchestra with an all-American program on October 19. This opens with the Drums Overture by James P. Johnson, the stride piano pioneer whose hit songs included “The Charleston,” and whose symphonic music Alsop has played a significant part in rediscovering, recording and championing. Copland’s Fanfare for the Common Man will be heard alongside Joan Tower’s Fanfare for the Uncommon Woman, a work dedicated to the conductor, as well as three 20th-century staples: Barber’s First Symphony, Gershwin’s Rhapsody in Blue and “Three Dance Episodes” from Bernstein’s On the Town. A former protégé of Bernstein’s, Alsop is widely recognized as one of the foremost exponents of his music.