An example with which I’ve tried to reproduce what Brian described here
The album (let me know if you need a “debug copy” or if it’s available to you):
Track 8 has no composer credits (allmusic doesn’t know about it).
Now adding the composer manually …
… get’s me this:
If I un-ID the album, I see this:
Note: since I’ve played with metadata afterwards I’m not sure if I still have a version in the state the album was when doing the test. Maybe I’ve some backup.
Update: interestingly, when I look at the album properties, I see this:
I’ve applied Tony’s work/part trick … and with this I can switch it on and off.