200 chart and was No. 1 on its Classical Albums chart from January 1969 to January 1972. It was the second classical album to sell over one million copies and was certified Gold in 1969 and Platinum in 1986 by the Recording Industry Association of America. Carlos performed selections from the album on stage with a synthesizer with the St. Louis Symphony Orchestra. The massive and unexpected success of Switched-On Bach put tremendous and unwanted pressure on Carlos. She was by this time well into her gender confirmation process, and she was understandably fearful of both personal ridicule and physical attack, and of the negative impact that her status as a transitioning person could have on her music career. Biographer Amanda Sewell records that the St. Louis appearance was extremely difficult for her -- she hated having to disguise herself as Walter, for which she had to affect a deeper voice, use makeup to simulate a five o'clock shadow, and don a wig and pasted-on fake sideburns. Her childhood experiences of being bullied and assaulted made her so fearful of appearing in public that she reportedly even contemplated taking her own life before the event and reportedly cried all the way to St. Louis. This was to be one of only two live performances Carlos made following her days as a student, the other being with the Kurzweil Baroque Ensemble for "Bach at the Beacon" in 1997. In 1970, the album won a Grammy Award for Best Classical Album, Best Classical Performance – Instrumental Soloist or Soloists (With or Without Orchestra), and Best Engineered Classical Recording. Carlos released a follow-up, The Well-Tempered Synthesizer, with synthesized pieces from multiple composers. Released in November 1969, the album reached No. 199 on the Billboard 200 and received two Grammy nominations. The success of both albums allowed Carlos to move into Elkind's more spacious New York City home in 1971. Carlos considers Elkind's contribution to her work, and specifically Switched-On Bach, to be underappreciated, calling her "a 'silent' partner" and her work "critical to my success". 1970s After the release of Switched-On Bach, Carlos was invited to compose the soundtrack of two science fiction films, Marooned (1969), directed by John Sturges, and A Clockwork Orange (1971) by Stanley Kubrick. When the directors of Marooned changed their minds about including a soundtrack, Carlos chose to work with Kubrick, as she and Elkind were fans of