在戲文中標明「合」字之處，其「合」字有二義：一指「合唱」，一指「合頭」。凡一調叠用數曲，末幾句文字相同，就稱作「合頭」，在第一曲合頭處上註一「合」字，第二曲以下不再重出曲文，僅註「合同前」或「合前」。 偶然閱讀到錢南揚先生對於「合頭」與「合唱」的解釋，便希望能透過錢南揚與其他學者的解讀，對《永樂大典戲文三種》中標註「合」字之處的曲文加以分析。除判別曲文中「合」字標註所表明的意義為「合頭」或「合唱」，也透過與《九宮大成南北詞宮譜》的對照，針對曲調中「合頭」的現象作進一步的探討，了解「合頭」在曲文中使用的情形，以及因曲文形式的轉變，「合頭」意義也隨之產生的變化。 文末根據統計與分析結果，將合唱略分為「旋律固定」與「旋律不固定」兩類；將合頭略分為「曲文相同」一類、「曲文不同」四類，合計共五類。此外，曲文中亦有「合唱兼合頭」的現象存在。

The notation “hé (合)” of Chinese opera script have two meanings：one is “chorus”, another one is “hé tóu (合頭)”.When the author use the same melody more times, the final skit is same, and it’s called “hé tóu (合頭)”. At the first melody’s “ hé tóu (合頭)” note a notation “hé (合)”, after the first, the same melodies will not show the same skits, it would note “hé tong qián (合同前)” or “hé tóu (合頭)”. I read the explanation about “chorus” and “hé tóu (合頭)” by Qián Nán Yáng, so that I want to know more about this from another scholars and to analyze the notation “hé (合)” of “Yongle Great Encyclopedia scripts (永樂大典戲文三種)”, determined the notation “hé (合)” is mean “chorus” or “hé tóu (合頭)”. And I will consult “Jiǔ Gōng Dà Chéng Chinese opera music book (九宮大成南北詞宮譜)” to discuss more about “hé tóu (合頭)”. According to the account and analysis, I differentiate “established rhythm”and”unestablished rhythm” of chorus，and I differentiate five kinds of “hé tóu (合頭)”. By the way, there have an appearance is “chorus with hé tóu (合頭)”