Pianist Ekaterina Willewald, a favorite at the IM+SC, will offer a mesmerizing performance of “The Blue Danube,” a captivating program exploring the rich heritage of the waltz, celebrated as the most beloved dance among Europe’s greatest composers, including Chopin, Schubert, Brahms, Tchaikovsky, Rachmaninoff, Sibelius, and, of course, Strauss.