It's time for the choir to start rehearsing in earnest, but the AC is broken and it's too hot to think. They move to somewhere cooler, and Rika gives them a song to hone their rhythm. Then, they're swept up in a series of inexplicable events!
This is making it hard for me to remember. 
You guys have fun.
هذا يعسّر عليّ التذكّر، تكفّلوا بالباقي
Jetzt hab ich den Faden verloren …!
Me cuesta recordarlo.
Encárguense ustedes.
Me cuesta recordarlo.
Apañaos vosotros.
Je vais finir par oublier le début.
Débrouillez-vous.
Accidenti, così non me lo ricorderò mai.
Agora está mais difícil de lembrar.
O resto é com você.
Вы мешаете мне вспомнить. 
Развлекайтесь сами.