Actress Jill Clayburgh danced to Tchaikovsky’s Swan Lake in her New York City apartment in Paul Mazursky’s 1978 film ‘An Unmarried Woman’. “I haven’t seen the 1978 film since I was a teenager…that scene stayed with me: exuberant, silly, creative, full of possibility,” she said. The film, which was released in 1978, also starred Melanie…