I tried this, and all it showed was the duration of the individual tracks. This became redundant.
Ex.
album "Ginger Baker's Air Force" has 8 tracks. Showing album by itself shows 1:18:13 on the bottom bar. I need a field that will show 1:18:13 for all 8 tracks, so that I can sort and quickly determine how many new items I have that fall into the time categories. In this instance, string values would not matter as long as tracks within an album were grouped together when I sorted, and the only issue would be if there were multiple albums with the exact same duration.
Also, unless I can force an album with one track to be a complete album, I cannot use a complete album string because many of the albums that I have are one album, one piece of music, one track. Or they are individual radio programs or podcasts.
Also I'm not sure where rating comes into it. I work without rating tracks. If I didn't think it were 5-star it wouldn't be in my library, so rating is useless to me, and I normally take it out of every view (I'd like to completely take it out of the program so that it would never show up).
Perhaps a better way to ask the question is: Can I base a custom duration field on the sum of all matches in a master field?
But thanks for your input.