What adjustment to the page http://www.chrisjj.com/tango/cjjsets/ will solve Blogger's "Blog List" gadget's failure (below) to detect the RSS feed?
Acctually blogger program can't 'read' feed page like (http://www.chrisjj.com/tango/cjjsets/) . But blogger Feed widget can read RSS format like xml. it's look this site have register third party feed XML feed. You can try paste this link (http://feed43.com/chris_milonga_dj_setblog.xml) to Blogger Feed Widget . Tested, it's working. Because Blogger Feed Widget can read it
This could be number of reasons but I would start by using the browser console tools and also making sure that the rss service is even running on the remote site.