Is it illegal to use a cover song in a youtube video?

Question

and is it illegal to play a song while in a video? like in the background on youtube or something?

Answer 1

Yes, copyright etc.

Answer 2

Generally, if you are making profit by using someone else's work, you are doing something illegal.

However, on youtube, you get no money (mostly) and you are using it for entertainment. Also, by giving credits to the artist, you are not trying to steal it from them

Another thing, you upload a vid with no intention of distributing it.  

Answer 3

no, just title it "cover song"  everyone does it even me!