Problem
To my way of thinking;
a 'compilation' album, collects a sample of an artists work, produced over a period of years.
a 'Various Artists' album is something else

Over time, I've associated the original issue date with tracks on 'compilation' albums.

As a new user, I'm experimenting with various sidebar sorts.
I've just sorted my albums in the sidebar, using 'Group by Album artist/Year - Album'.
But the 'compilation' albums were separated further by the year the individual track was released.

I then experimented with 'year' and 'original year'.
Displaying both fields in the Playlist view, it appears that if you change one of the fields, the other changes as well, i.e.
change the date in 'year' and the 'original year' date changes
change the date in 'original year' and the 'year' date changes

It would be useful in the 'compilation' scenario to have a 'year' for the album release and 'original year' for the track release date. This is impossible to achieve if the fields cannot be independently populated.
Or am I doing something wrong?