Looks like Xi didn’t read the fine print of their Legal Friendship Agreement :/
Transcripts
Panel 1: Rho, Sigma and Xi in a band practice. Rho has an electric guitar, Sigma is on the keyboard and Xi’s on the back with the drums. Rho gets ready to start, and says “One! Two! Three! Four!”
Panel 2: The apartment building seen from the outside. We can see wiggly, badly drawn music symbols coming from the apartment.
Panel 3: A close-up of Xi, holding her drumsticks with an angry, frustrated expression.
Panel 4: A close-up of Sigma, looking a little nervous. He says “Uhh…”
Panel 5: A close-up of Rho, sweating with a nervous smile. He says “P–practice makes perfect, guys!!”
Panel 6: Xi, still at the drums, looks angrily at Sigma and says “Why are we doing this?”. Sigma turns to her and says “Because we have to help our friend!”
Panel 7: Sigma turns his head away from Xi, who is still angry, and says “It’s part of the contract.”