Nono returned to the piano (with tape) for his next piece, "... sofferte onde serene ..." (1976), written for his friend Maurizio Pollini after the common bereavement of two of their relatives (See Nono's Programme note|Col Legno,1994). With this work began a radically new, intimate phase of the composer's development—by way of "Con Luigi Dallapiccola" for percussion and electronics (1978) to "Fragmente-Stille, an Diotima" for string quartet (1980). One of Nono's most demanding works (both for performers and listeners), "Fragmente-Stille" is music on the threshold of silence. The score is interspersed with 53 quotations from the poetry of Hölderlin addressed to his "lover" Diotima, which are to be "sung" silently by the players during performance, striving for that "delicate harmony of inner life" (Hölderlin). A sparse, highly concentrated work commissioned by the Beethovenfest in Bonn, "Fragmente-Stille" reawakened great interest in Nono's music throughout Germany.