In 1999, several composers turning 50 years old were invited to compose a new piece for The Downtown Ensemble in New York. LowBirds uses a set of motivic menus and an architecture that shows where—but not how—to play the motives. Even where no pitches are specified, the composition becomes expressive and interactive. Lush and atmospheric, LowBirds has been heard in small, diverse spaces from Pauline Oliveros’s Deep Listening Center to Amsterdam’s Zaal 100. (LowBirds is part of a set for various instrumentation that also includes Mirrored Birds, Middelburd, and HighBirds (Prime)–In Memoriam Iannis Xenakis.)