Whenever the Master was singing in a group and heard something that he liked, he inevitably asked to have it sung again, and only then would harmonize with it.Confucius, & Slingerland, E. (2003). Analects: With selections from traditional commentaries. Hackett Publishing.
If the Master was singing with others and one of them happened to be particularly good, he would invariably ask the person to repeat the piece and then he would join in.Confucius, & Watson, B. (2007). The Analects of Confucius. Columbia University Press.