If you are looking for high-quality music videos without the risk of a virus, the open directory method is largely obsolete.
The search string is a specific type of "Google Dork"—a search query designed to bypass standard website interfaces and dive straight into the open directories of a web server. Intitle Index Of Mp4 Music Videos
If your goal is to watch videos without ads, you can actually paste a YouTube URL directly into VLC ( Media > Open Network Stream ) to watch it in a clean, standalone player. If you are looking for high-quality music videos