Gakunoya

…However, today, the nature of the dressing room has become flattened across the board, including in traditional theater, and in many cases, as is the case with the dressing rooms in many multipurpose halls, they often serve no more than as a waiting room.
[Gagaku]
In the past, it was also called Gakunoya. It is the place where musicians perform during Bugaku and where dancers put on their costumes, and the place where musicians and dancers rest is also called "Gakuya."

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

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…しかし今日では，楽屋のそのような性格は，伝統演劇も含めおしなべて〈平板化〉しており，多くの多目的ホールの〈楽屋〉がそうであるように，単に〈控え室〉以上の意味はもたぬ場合も少なくない。劇場舞台【編集部】
［雅楽］
　古くは楽之屋（がくのや）ともいう。舞楽のときに楽人の演奏する場所，また，舞人が装束を着ける場所でもあり，楽人と舞人が休息する場所も含めて〈楽屋〉と呼ぶ。…

※「楽之屋」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