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.

'One7' holds a special place among the number pieces in several respects. For this work is the only number piece dedicated to a woman composer, Pauline Oliveros (born in 1932). Furthermore, the work is an 'extraction' from 'Four6'. Last but not least, there also exists a live reference recording of the composer for piano. For 'Four6' the pianist Sabine Liebner chose very distinct tonal characters or ways of playing for each of the four parts: one part plays the piano in the conventional manner, one uses a prepared piano, one plucks strings within the resonant space of the piano, and one produces noise-related sounds. The individual parts thus recorded were then superimposed in time, thus conveying the hearing impression of a live performance with four different musicians.