Erasures and Additions is a multi-movement piece created by alternately adding material to and taking material away from the preceding movement, beginning with john Cage's "Harmony 38', itself an erasure of a hymn by William Billings. (The Cage is not included as a movement in the work.) Additions are made by a random process designed to keep the statistical distribution of pitches and durations more or less equal to that of the preceding movement, with a chance determined number of notes (between one and five) to be added to each measure. Erasures are made according to a chance procedure, executed on each note of the preceding movement, that determine whether to erase all, more than half, less than half, or none of the note. Instrumentation is open, though the work is ideally performed by a quartet of sustaining instruments. The piece was written for Kristen Smiarowski's The Key Game Project: Sleep, Staring, Well, The recordings, above, were made during a performance of Sleep, Staring, Well during its initial run, which occurred at Automata, Los Angeles in January 2014.