The longest and at the same time most complex of Bartók’s six string quartets was composed in the summer of 1934 as a well-paid commission for the renowned Elisabeth Sprague Coolidge Foundation in Washington. Bartók wrote it in a few weeks in Budapest. The substantially reworked autograph shows us how hard he laboured on the elaborate five-movement form. In the run-up to the premiere, he clarified numerous questions concerning the execution – including specific practice instructions for the “Bul...