Stockhausen made Cologne an important centre for electronic music. He also helped to make the Darmstadt Summer Courses a famous centre for modern music. He did not invite John Cage to lecture there in 1958. This led to disagreements with Boulez and Nono. In California in 1967, Stockhausen married his second wife who was a painter. During the 1960s he bought land in the country near Cologne and had a house built there. Stockhausen did not design the house himself, because he was not an architect.