“Music is anything I perceive as beautiful that resounds inside of me,” says bass virtuoso William Parker. “My musical world relies on the intuitive now—my job as the composer is to give all the musicians permission to soar and engage in the spontaneous moment.” In a pair of world-premiere programs, Parker is joined by two ensembles comprised of an extraordinary group of artists. The evening’s first set, Before I Went to Sleep, Mother Would Put a Clothes Pin on My Nose, reflects on Parker’s own story and the lingering effects passed down from more than 300 years of slavery in North America. Following an intermission, Parker leads a unique sextet featuring instruments from Asian, African, and American traditions in a program entitled Flexible Showers of Sound.