Bartk’s Second String Quartet was composed – with several long interruptions – between 1915 and 1918, after he had spent several years almost solely devoted to collecting folk music. The melody and rhythms of the riotous middle movement “Allegro, molto capriccioso” provide impressive testimony of how his research trips had taken him as far as North Africa. The first edition of this quartet, published in Vienna in 1920, contains a conspicuous number of errors that were only partially corrected in a later revision undertaken by Bartk. As late as the 1940s he noted changes in his personal copy of the score that have never previously appeared in print. These late changes by Bartk are taken into account in this definitive edition of the string quartets supervised by Bartk scholar Lszl Somfai, with problematic passages in the sources carefully documented. It is the first-ever Urtext edition of this work.