"Gwlad! Gwlad!" (Wales! Wales!)

Azusa (and the rest of Rikka High School band) are performing "Hen Wlad Fy Nhadau", Welsh national anthem, one of the most powerful anthem I ever heard, with proud, joy and determination

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"Gwlad! Gwlad! Pleidiol wyf i'm glad!
Tra môr yn fur i'r bur hoff bau
O bydded i'r hen iaith barhau"

Chanted by audiences, including Kumiko and others who are visiting Rikka High School Proms (another BBC Proms based fictional events)