So, there are a bunch of standard columns in the Product Listing table:

Code:
PRODUCT_LIST_MODEL,
PRODUCT_LIST_NAME,
PRODUCT_LIST_MANUFACTURER,
PRODUCT_LIST_PRICE,
PRODUCT_LIST_QUANTITY,
PRODUCT_LIST_WEIGHT,
PRODUCT_LIST_IMAGE
So let's say I want to add the music genre as a column into the Product Listing table, and only show it when I'm showing a particular category in my shop (the music category).

Are these the steps I have to make:

1) Add a new configuration entry with configuration_group_id = 8
2) Add this new configuration entry into includes/modules/pages/index/main_template_vars.php (how do I override this?)
3) Add to includes/modules/<template>/product_listing.php

... I'm lost.