What happened to Walter Carlos?

In 1939 Walter Carlos was born in Rhode Island. In 1968, he used a Moog synthesizer (an analog synthesizer) to record J.S Bach's music and made a name for himself in the musical field. In 1971 he wrote and performed the musical score for A Clockwork Orange. In 1972 Walter had a sex change operation and changed her name to Wendy. She has stated that ever since she was a child, she felt that she was more feminine than masculine, always having a liking for long hair and female clothing. In 1979 she came out with her operation in Playboy, she had been keeping it a secret from the public and used this as an outlet to liberate herself further.

As far as the use of Singing in the Rain in A Clockwork Orange, initially I would've thought that it was the director's stab at irony. Using a cheerful, playful song to remind the audience of a reality which is non-existent in the world of Alex DeLarge. But, when I researched it, it is said that Stanley Kubrick wanted to make the scene where the thugs attack the writer and his wife. He asked him to dance and sing during it and Singing in the Rain was the only song he knew all the words to.