Ahh!!!
This is exactly what I have been trying to do!
I had never really been a fan of panes.... I didn't like the look of the window up top, so I just sorted by Filename(path) with my artist/album directory structure, and had MC display Album Thumbnails. Then I could scroll thru all the alphabetically arranged Artist/Album thumbnails.... and the "Show Files" at the bottom gave me a good look at whatever I needed when I wanted details. I never "clicked into" the album thumbnails.....I use the 1 level view, and get to details of the tracks via the list at the bottom.
Now, I just started playing with the Thin Panes.... and I love them! Gives easy browsing/selection....but without hogging up screen real estate with ugly text boxes. (I am a fan of showing as much art as possible).
I spent a fair bit of time trying to get the file list to show up at the bottom of this view before finding out it seems to not be possible.
What Alex B has mocked up is indeed my dream set-up.
+1 to this request.......