I think that "Never go mainstream" is a good rule of thumb to follow. It's been said time and time again by Maikel and other people that mainstream nightcore is bad, that it's a respect issue, etc.
Given the current state of mainstream music, it's generally best to stay away from any song that's playing on the radio.
Here are some reasons I thought of on why you should avoid nightcoring mainstream songs:
- Nightcoring mainstream songs disregards the definition of nightcore set forth by its founding fathers. It basically throws the definition out the window (for lack of a better term). For more information, see this thread: http://www.nightcoreuniverse.net/viewto ... =11&t=1316
- Mainstream songs have been "nightcored" countless times already. Your upload is likely to be buried deep in the Youtube search pages, meaning that it will be hard for people to find your video, and you won't gain much views.
- Mainstream songs tend to have more copyright problems (at least in my experience). They are more likely to be blocked by record companies, generate copyright strikes, and have ads next to the video.
- If you do decide to create an account on Nightcore Universe, you won't be allowed to post your videos or channel here. This forum has members that are very knowledgeable in nightcore who can help you improve and get your channel going. They are more likely to help you (and respect you) if you go the extra mile to make sure your videos/channel adheres to the Nightcore Posting Regulations (Link: http://www.nightcoreuniverse.net/viewto ... =11&t=1349).