To me, the core of Star Trek is to tell good Science Fiction stories through the lens of the Enterprise crew.
This is a really good example of that. The basic idea is an exploration of a common trope of SF, exploring some ideas of more alien lifestyles. It’s carried through well here, particularly through the relationship with Troi (the first time that I’ve actually liked her in the series).
Riva’s chorus is implemented well, with the concept settling in quickly without being beaten over the head with it. Although there is a slightly unsettling overtone with the caste-like system of the chorus – it would have been interesting to come back to this setting again.
137 down, 600 to go.