Chromecast-like functions on second monitor

[doghets]

Hi all! A friend of mine, who like karaoke, asked me something I tried to search myself but with no results. What he wants is to "pin" the youtube video player on the second screen (fullscreen) and on the main screen he wants to be able to search and choose the video (or next video) to play always on the second screen. This "function" reminds me alot the chromecast, where you stream to a screen the video you chose without seeing it on the main monitor, and at the same time you don't see what you are doing/searching on the display where you stream the video. I hope that this description is not confusionary! Also I want to add that this friend of mine is not an expert, so if there is a solution to this problem it must be simple as possible, if possible obviously!

Thanks in advance!