I have updated the link above, and it is now working! My mistake; anytime you see "Content.OrlandoDrummer.com" in a link, it's referencing an older subdomain. Remove the word "content" from the URL and all those links will work, should you stumble across any others.
In terms of locating lessons in the future, remember to use the Search feature on the main menu of the site. You can simply type the word "Technique" and every lesson on the site that contains information on that topic will appear.
Hope this helps!