Although this is ostensibly about Greg, Rose gets some subtle development as well.

This episode is just filler, pure and simple.
Stevonnie takes the stage again in a surprisingly serious episode.
I am constantly amazed at how much thought went into developing side characters like Lars.

Peridot gets to do a little self-discovery, with adorable results.
After a season or so that’s been light on the songs, the show goes all in for a full-blown musical episode and it is glorious.
Sour Cream gets to sort out his daddy issues!