After the Mysterious Discovery club doesn't get promoted to an official club due to not doing anything noteworthy, Tanako decides to form a band of all things to promote the club and get new members.
All the members try to recruit people, but Tanako is the only one who manages to get anyone, and brings some members of the disciplinary committee in to play instruments, and none other than Rurumo to sing.
Turns out Rurumo is great at singing, so the band starts out well and they progress through the competition that they wanted to enter pretty quickly.
I don't really want to spoil any more, but it doesn't go as well as it could have after that.
Overall I really enjoyed the episode and thought it was more of a return to the standard set by episode 6. The next (and final?) episode looks like it will be pretty cool too, from the preview.
Bonus end slate: