Is it legal to make a music video to a Copyrighted song and upload it to the Internet (Youtube, Vimeo …)
– Emil
No.
…
Absolutely not.
well…that kinda makes 0.000001% youtube content legal.
im not sure its explicitly illegal, but i cant give an definitive answer.
It’s not legal, but it seems to be a tolerated ilegality, at least in Youtube 
Just write in the video and somewhere in youtube that you aren’t the author, make clear that the dude that made the soung as nothing to do with you or your project and don’t forgeth to refer is name ;). Ho! And in the title of the video write someting like " homenage to <name of the song> video by danmark0992.
This still doesn’t make it legal in any way, but raises the chances that no one flag your video hehe
Vimeo seems to be more restricted, if it isn’t yours you’ll be baned 
so it’s probably better stick only to youtube.
There are some situations where something is copyrighted - but you can still copy it freely.
Take the current NIN release. It was released under a Creative Commons license that allows you to create derivative content as long as it was non-commercial, you made your work available under the same license, and gave attribution.
In that situation, it would be perfectly acceptable to use the music to create a music video and release it (as long as you adhered to the CC licence). The stuff is still copyrighted, but doesn’t mean you cannot copy. It means the rights relating to copying are with the creator. Most of the time, creators retain sole rights for re-distribution, but it is a requirement for something to be copyrighted.
So, while (most of the time) the answer is “no, you cannot copy it” … the longer answer really depends on what actions the creator wishes you to have.
It is illegal.
Youtube tends to brush the line with legality, though. They don’t take down video’s unless there’s a copyright claim by the respective company. Hence the vast number of music videos and movie clips that are on youtube.
Thanks, for the comments…
it is hard to “become wise on” all the copyright rules
–Emil
Do it anyway.
People are using the word “illegal” I little bit to harshly. It’s a gray area, and if you have some knowledge, you can justify what you want to do through fair use…
http://www.copyright.gov/fls/fl102.html
I love justice, but c’mon, is making “unauthorized” art a crime if it only makes the world more beautiful and interesting? Everything you see and hear is copyrighted by someone else, but you shouldn’t let copyright regimes prevent you from participating in your own culture.
“Fair use” gets thrown around a lot by everyone. In truth there is very little that really falls under fair use, and this isn’t one of them. Also be aware the fair use is defense not a right, so even if you think fair use may apply you can still get sued and have to prove it in court.