ACO’s seasonopener features a rare performance of orchestral music by the pioneering composer and performer Meredith Monk with members of her ensemble. (Monk is holder of the Richard and Barbara Debs Composer’s Chair at Carnegie Hall.) Genre -bending, -skipping and -skirting vocalist and composer Theo Bleckmann, a Monk protégé and longtime member of her inner circle, performs a new song commissioned especially for the occasion. The concert also features the premiere of the raucous first orchestral piece by experimental-rock guitarist Ian Williams (from the band Battles). ACO’s 2013 Underwood Emerging Composer Commission winner, A.J. McCaffrey, contributes Motormouth, a premiere that chronicles the shifting moods that he encounters as the parent of a toddler—from playfulness to delirium to sleepiness. Loren Loiacono a young woman of extraordinary talent, synthesizes her childhood experience playing with Barbie’s Dream House and her later discovery of Ravel’s Daphnis et Chloe in the NYC premiere of Stalks, Hounds.