Morton Feldman composed pieces where the sense of time disappears on the edge of silence. Organist Geerten van de Wetering will perform, in the Kloosterkerk, the only organ piece Feldman ever wrote: Principal Sound. However, this composition from 1980 could also be called ‘vintage Feldman’. Recognisable timbres and harmonies bring coherence to the piece. Not a single pattern is repeated; the music is constantly developing. As a listener you are urged to listen attentively and to immerse yourself in sound. This requires what is known as deep listening – a concept introduced by composer Pauline Oliveros, who died in November last year. We pay homage to her by putting on Bye Bye Butterfly, one of her trail-blazing electronic compositions from 1965. She deconstructed a gramophone recording of the love duet from Puccini’s Madama Butterfly using oscillators and reel-to-reel tape recorders. The composer wrote that her purpose was to ‘bid farewell not only to the music of the 19th century, but also to the institutionalised oppression of the female sex of that age’.