To composers in the then Communist Bloc in Central and Eastern Europe, Webern's music and its techniques promised an exciting, unique, and challenging alternative to socialist realism, with its perceived tendency to kitsch and its nationalist and traditionalist overtones. Whereas Berg's "Lyric Suite" may have influenced the third and fourth string quartets of Bartók in 1927 via an ISCM concert (in which Bartók himself performed his own Piano Sonata), Webern's influence on later composers from what became the Hungarian People's Republic and from other countries behind the Iron Curtain was sometimes mediated or obstructed by politics. As Ligeti explained to a student in 1970, "In countries where there exists a certain isolation, in Eastern Europe, one cannot obtain correct information. One is cut off from the circulation of blood." Nonetheless, Webern's work was a seminal influence on that of both Endre Szervánszky and György Kurtág following the Hungarian Uprising of 1956, as well as on Ligeti himself. Later still and farther east, Sofia Gubaidulina, for whom music was an escape from the socio-political atmosphere of post-Stalinist Soviet Russia, cited the influence of both J. S. Bach and Webern in particular.