A chance meeting at a concert in Basle brought together a composer and patron which would result in three mid-20th-century masterpieces. By then conductor of his own Basle Chamber Orchestra, Paul Sacher commissioned the Music for Strings, Percussion and Celesta from Bela Bartok, and it was followed within four years by the Sonata for two pianos and percussion, and finally the Divertimento, before the composer emigrated to the US at the outbreak of the Second World War. At this Viennese concert with the Philharmonia Orchestra, Christoph von Dohnányi paired it, as often before, with another work which expresses uncertainty in turbulent times, The Unanswered Question of Charles Ives.