Leonard Bernstein and George Gershwin, two of America’s greatest and most beloved composers, star in the electric season opener at the D.C. area’s Music Center at Strathmore. West Side Story, one of the best musicals of all time, reimagines Shakespeare’s star-crossed lovers Romeo and Juliet in gang-ravaged 1950s New York. Bernstein’s Symphonic Dances from West Side Story is a galvanizing work, the equivalent of a shot of espresso. Following that is Gershwin’s playful, jazz-influenced symphonic poem, An American in Paris, which captures the romantic beauty of the City of Light. Closing out this ebullient program is pianist Thomas Pandolfi, a leading interpreter of Gershwin, performing the legendary composer’s Concerto in F.