A ukelele band covering (and uncovering) a tune made popular by the rock band "Quiet Riot" (Umm! see the comments section for a correction, turns out Slade was the original band).
Not sure what the female stage manager has to say in French at the beginning of the video but I don't think it was very flattering.
From Ms. Francine, one of Earwigoagin's retinue of volunteer researchers, here is a rough translation of the opening comments;
".....she's basically calling the next number (next show or "spectacle") and then says something about him being petite (small) and he says "well its always worked for me" and she says "OK, whatever" then next show something something something, I can't really tell. But then she winks at the end."