Curved piece - Kyokuhin

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[Song Composition]
Among mainland gagaku pieces, there are those that consist of one volume (one movement) and those that are multi-movement, consisting of several volumes. There are also ranks (called "musical pieces") such as "large music," "medium music," and "small music" depending on the scale and status of the piece, and small music is often one piece per volume. Medium music can be in multi-movement form, and its basic form is composed of three parts: jo, ha, and kyu. However, complete pieces (e.g., Gojoraku in Heichou) are rare, and most are missing parts such as "ha-kyu" (Kaden in Ichigetsucho) or "jo-ha" (Kishunraku in Ouzhongcho), or only one volume of "ha" (Seioraku in Ouzhongcho) or "kyu" (Sandaisho in Heichou) has been handed down.

*Some of the terminology that refers to "curved products" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

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［楽曲の構成］
　大陸系雅楽曲には1帖(1楽章)で1曲をなすものと，数帖で1曲をなす多楽章形式のものとがある。また，曲の規模と格とによって〈大曲〉〈中曲〉〈小曲〉といった等級(〈曲品〉という)があり，小曲は多く1帖1曲である。中曲には多楽章形式のものがあり，その基本形式は序･破･急の三部分構成であるが，完備しているもの(例，平調《五常楽》)はまれで，多くは〈破･急〉(壱越調《賀殿》)，〈序･破〉(黄鐘調《喜春楽》)のように一部を欠いているか，〈破〉(黄鐘調《西王楽》)または〈急〉(平調《三台塩》)の1帖だけが伝えられている。…

※「曲品」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報