Green Screen / Chroma Key opinions

[The Lazy One]

Has anyone ever recorded a Dj Set with a Green Chroma behind for a video?

After you could put a black/dark background or something in post production.

is it worth buying a green cloth?

example:

[overcast]

Make sure you either have good lighting or purchase several lights if you want to have your chroma key look really good. You're going to want to have even lighting on the green screen to make sure it's one consistent color across. Furthermore, you're going to want to make sure the lighting on you doesn't cast too much shadow either. High positioning of lights would be best to achieve this. You'll probably also need a backlight as well to make sure there's a clear separation between you and the background. A fill light might not be needed for a smaller production, but it would look nice.

[vincearnone]

Overcast is totally right. It's all about lighting if you want to make it look really good. You want as even an off color as possible behind you. The $$ investment will be in lighting, not in the screen itself.

[The Lazy One]

i'll be following your steps