Schott established lifelong working relationships with Paul Hindemith and Carl Orff, and this commitment between composer and publisher has defined the character of the catalogue, involving some of the important composers of their time. Hans Werner Henze, for example, joined Schott at the age of twenty, his considerable oeuvre being published exclusively by them for over 55 years. Michael Tippett's lifelong relationship with Schott began in March 1939 when Willy Strecker visited London for the first (concert) performance in England of Hindemith's . Shortly after war had been declared, he heard through their London office that Schott would like to publish his Concerto for Double String Orchestra and an early Piano Sonata. "Being a born internationalist I thoroughly enjoyed this outcome and thought it a good omen." György Ligeti, Krzysztof Penderecki, Alexander Goehr and Aribert Reimann have all been published exclusively by Schott for more than thirty years.