Is there a safe website that lets you download karaoke videos off of youtube and is legal?

You can use dvdvideosoft’s youtube to mp3 converter.
if you use firefox, it will also install a plugin, that will put a “download mp3” button below the youtube video, that will download the video and automatically convert it to mp3 for you.
Make sure to do a custom installation and deselect all the adware that it wants to install.

Real player will do it. It will also strip off the audio for you and make them MP3s

Be aware that, whatever software you use, the only legal way is to contact the copyright holder for the video (which is not necessarily the person who uploaded it) and get their written permission to download it. Without their written confirmation it’s all illegal.

Real Player has a download option. Sites like Keepvid may or may not work. They should have an option to download entire video.

http://www.listentoyoutube.com/ is a good online site. All it does is takes the MP3 from a video. The only thing needed is the link for said video and the site does the rest.