What kind of repertoire can be called the traditional repertoire of a genre? Is traditional repertoire exclusively unique to a genre? Thanks!

Traditional repertoire is not necessarily unique to a genre!

The so-called traditional is the counterpart to the new, and almost all styles of theater have a classification of traditional and new plays. The traditional plays are those that appeared after the birth of the genre and have been performed and refined for a long time, while the new plays are, as the name suggests, newly written plays that have not been tested by long performances. So like the Peking Opera's "Qin Xianglian", "Four Lang Visiting Mother" and so on is the traditional repertoire, while the famous Peking Opera's eight model operas are not; Huangmei Opera's "Match of the Immortals", "Cowherd and the Weaving Maiden" and so on is the traditional repertoire, and the Yellow Plum Opera's "Thunderstorm" "Song of Everlasting Hatred" and so on is not;

wearing costumes is not necessarily the traditional repertoire, and the most obvious is the Peking Opera's new play "Prime Minister Liu Luoban", "Divine Eagles" "Eagle Shooter Legend of Heroes", "Thin Horse Royalty", "Dream of the Red Chamber" of Huangmei Opera, "Ban Zhao" of Kunqu Opera and so on.

In fact, this is not a conflict at all. For example, the play "Qin Xianglian", inside the Beijing Opera, inside the opera, but he is both the traditional repertoire of the Beijing Opera, but also the traditional repertoire of the opera; and what you said, "Song Jiang kills Shijie" (in the Beijing Opera is also called the Oolong Yard), it is the traditional repertoire of the Beijing Opera. So that kind of problem doesn't exist!