Composer tags are there in all of them and if you look in the track credits they are there in all the tracks. How is it decided to display or not?
It depends on an internal metric of interestingness and some contextual information from the album genres (Classical/Jazz/Vocal albums are more likely to show composer credits than other genres).
We use interestingness metrics to govern many aspects of composer and work display because if we showed them in every situation where we have data (keep in mind–every track with a composer credit is conceptually a performance of a composition by that composer), the result would be tedious and verbose.
We’ve tried to strike a balance that displays the information when it’s most relevant and keeps it out of your face (in places like the credits popup) otherwise.
I’m 100% sure we will iterate on this scheme many times before it becomes stable long term. I think there’s a little bit too much magic in it right now.