Cage composed his Number Pieces during the last six years of his life. Their titles indicate the number of performers or parts. Their notation is based on fixed and flexible "time brackets." the fixed brackets show when a musician should begin and end a pitch or tonal event. With the flexible brackets, the interpreter decides, within a predetermined time frame, when an instrument enters and when it falls silent. This disc featuring pianist Sabine Liebner explores two of Cage's late masterworks.