Flotation Device previews several enticing Northwest new music events, with Seattle Symphony premiering works by Joan Tower and Christopher Theofanidis, Seattle Modern Music tackling Ligeti’s Piano Concerto, Emerald City Music presenting a new chamber orchestra arrangement of Simeon ten Holt’s minimalist epic Canto Ostinato, and the Wayward Music Series hosting a Spring Convergence of notable Washington improvisers. We’ll use the occasion to examine the Ligeti/Nancarrow connection and the shared Tower/Theofanidis lineage of American neotonalism, and to explore Canto Ostinato’s open instrumentation in a montage of seven different recordings. Plus José M. Sánchez-Verdú finds new sounds on old instruments, Jessica Lurie jams with the Fred Frith Trio, and Harriet Tubman releases their first album in eight years with help from vocalist Georgia Muldrow. A first look at Miroslav Vitous’s new valedictory album Mountain Call rounds out this wide-ranging program.