In September 1968 Adorno went to Vienna for the publication of "Alban Berg: Master of the Smallest Link". Upon his return to Frankfurt, events prevented his concentrating upon the book on aesthetics he wished to write: "Valid student claims and dubious actions," he wrote to Marcuse, "are all so mixed up together that all productive work and even sensible thought are scarcely possible any more." After striking students threatened to strip the Institute's sociology seminar rooms of their furnishings and equipment, the police were brought in to close the building.