This song "Wan Feng" ( Cold Breeze At Night), was written & completed by Dr. James, Wong Jim at 2 am . in an hotel. He was so happy that he phoned up Sally Yeh( Yip Sin Mun) to come to the hotel for try singing. She was delighted and went. With the success of the Mandarin Version, he later completed the Cantonese version to suit the Hong Kongites (Hongkis). What a great master piece he left for the younger singers to enmulate . With deep respect to the "Kwai Choi song writer ", From Malaysia Terima Kasih. TQ, ( Dor Jeh).
Your source needs verification. It was not a common practice in the 80s that a local Cantonese songwriter wrote a movie themesong in Mandarin before Canto. But anyway I read a James Wong column in Ming Pao at that time，briefly before the movie was staged probably as part of promotion, that Sally Yeh finished the recording in one take. James Wong highly praised her talent.
