four times and played some of the longest works he had written to date: he premiered Opus clavicembalisticum and his Fourth Sonata in 1930 and his Toccata seconda in 1936, and he gave a performance of Nocturne, "Jāmī" in 1931. Years of seclusion Ups and downs in life and music (1936–1949) On 10 March 1936 in London, the pianist John Tobin played a portion of Opus clavicembalisticum. The performance lasted 90 minutes—twice as long as it should have. Sorabji left before it finished and denied having attended, paid for, or supported the performance. A number of leading critics and composers attended the concert and wrote negative critiques in the press, which severely damaged Sorabji's reputation. Sorabji gave the premiere of his Toccata seconda in December 1936, which became his last public appearance. Three months earlier, he had said he was no longer interested in performances of his works, and over the next decade, made remarks expressing his opposition to the spread of his music. Sorabji eventually placed restrictions on performances of his works. These became known as a "ban", but there was no official or enforceable pronouncement to this effect; rather, he discouraged others from playing his music publicly. This was not without precedent and even his first printed scores bore a note reserving the right of performance. Few concerts with his music—most of them semi-private or given by his friends and with his approval—took place in those years, and he turned down offers to play his works in public. His withdrawal from the world of music has usually been ascribed to Tobin's recital, but other reasons have been put forward for his decision, including the deaths of people he admired (such as Busoni) and the increasing prominence of Igor Stravinsky and twelve-tone composition. Nonetheless, the 1930s marked an especially fertile period in Sorabji's career: he created many of his largest works and his activity as a music critic peaked. In 1938, Oxford University Press became the agent for his published works until his death in 1988. A major factor in Sorabji's change of attitude was his financial situation. Sorabji's father had returned to Bombay after his marriage in 1892, where he played an important role in the development of India's engineering and cotton machinery industries. He was musically cultured and financed the publication of 14 of Sorabji's compositions between 1921 and 1931, although there is little evidence that he