Many of Ligeti's earliest works were written for chorus and included settings of folk songs. His largest work in this period was a graduation composition for the Budapest Academy, entitled "Cantata for Youth Festival", for four vocal soloists, chorus and orchestra. One of his earliest pieces now in the repertoire is his "Cello Sonata", a work in two contrasting movements that were written in 1948 and 1953, respectively. It was initially banned by the Soviet-run Composer's Union and was not performed publicly for a quarter of a century.