Ok, you asked for it.
The trick relies on Media Center's stages for preparing a view for presentation: there's the file filtering stage, and the file list stage. By using Media Center's
expression language, we can have MC tally tracks per album, and store those in a user-defined calculated field (or an expression column or category in a view).
I'll have you create a new view, so that you can see how it works entirely in one view. You can apply this more globally later. Here are the basic steps:
1. Create a new Panes view under Audio, name it whatever you want.
2. Customize the view's Set rules for file display, click Import/Export and append the following search query:
[=save(0,v_tracks[album artist (auto)][album])1]=1 [=save(math(1+load(v_tracks[album artist (auto)][album])),v_tracks[album artist (auto)][album])1]=1
This is the per artist/album track accumulator.
3. Add a new column in the file list, making it an expression column with the following expression:
load(v_tracks[album artist (auto)][album])
or as a more formatted:
[Track #] of load(v_tracks[album artist (auto)][album])
This should now be working when you enter the view.
To apply it more globally, you can apply the search query you set in the Set rules for file display instead to the root Audio group in the tree (and by default all the subordinate views will inherit this rule), so that when you select audio from any Audio view, the counts are already complete. You can create a user-defined expression field named [# Tracks Album], which you'll first set to type Integer, Relational - one per Album (save the settings, and then re-open the dialog) and then set it to be Calculated, using the formatted expression above. Then, add this field as a column in the Playing Now playlist view.
It is important to note: this technique relies on MC's new global variables in the expression language, and the results of the calculated field (or view's expression column) require that the Set rules for file display are run once before use. This means, you need to show the relevant audio view at least once per MC launch before the values will be set.