National divides aside, the answer would appear to be Rachmaninov, Webern, Ravel, Stravinsky and (closer to home for this San Francisco-based ensemble) Charles Ives, as works by these composers, plus 78rpm records, piano rolls and traditional Eastern European themes, are woven into a musical tapestry entitled Prelude To A Black Hole.
For the second half of the concert, the big screen behind the quartet bursts into life, as Beyond Zero: 1914-18 - Bill Morrison's assemblage of archive film and Aleksandra Vrebalov's musical composition - follows a path through an artillery barrage of repeated rhythms and brief but expansive moments of release to depict war and moral chaos.
Scratches, burns and bubbles crawl across the nitrate footage like some living, viral thing, as images emerge from, and are then consumed by, the organic beast of history. The jolly pride of signing up and undergoing training is suddenly undercut by a brutal edit that shows dead bodies on the battlefield and planes falling from the sky. But if it's true that a picture is worth a thousand words, then the Kronos Quartet prove that, in the right context, a chord is worth a thousand pictures, whether an atonal assimilation of a world torn apart or a classical Turkish lament that carries the unbearable pain of all humanity in a single note.