 His father , Simon Stockhausen , was a schoolteacher , and his mother Gertrud ( née Stupp ) was the daughter of a prosperous family of farmers in Neurath in the Cologne Bight . A daughter , Katherina , was born the year after Karlheinz , and a second son , Hermann @-@ Josef ( " Hermännchen " ) followed in 1932 . Gertrud played the piano and accompanied her own singing but , after three pregnancies in as many years , experienced a mental breakdown and was institutionalized in December 1932 , followed a few months later by the death of her younger son , Hermann ( Kurtz 1992 , 8 , 11 , 13 ) . 
