One of the minor aspects of mysticism Kaikhosru Shapurji Sorabji was aware of was number symbolism, which forms part of every ancient set of occult beliefs. The fact of Sorabji's homosexuality was kept entirely private. In England during most of his life, homosexual acts between men, even in private, were illegal. Sorabji complained early on to Philip Heseltine that a young musician in England would have difficulty finding friends, due to the tendency of being mocked for one's musical abilities. As Sorabji held the copyright, he could prevent performances and recordings, regardless of publication of a score. In the 1950s Sorabji contemplated making a recording by himself but came to reject the idea. Clinton Gray-Fisk, Frank Holliday, Erik Chisholm, and others observed that Sorabji was very reluctant to record his published works. Sorabji's last public appearance as a pianist was in December 1936.