Music is a work of art an artist creates. The maker of this music, song, art should have the rights to all commerical uses of it. It's up to them to decide how it is to be used and by whom.
Movie companies have to secure the rights or permission from the owners of the music to use it in a commercial products such as a movie or product commercial. You might say, well my viemo or youtube little movie is non-commercial. Actually it is since these are web sites and companies who profit from the content.
You are basically taking someone elses product, a song, and you are deciding to expose it on youtube or vimeo where anyone can steal the content. You are deciding how the song will be used and where it will be on the web without asking the owner of that song if they are ok with your decisions.
Fact is, it is not yours. You can buy the song and listen to it as much as you want. But taking it to make your little movies seem better is not right. If you want music in your videos, make it yourself. Buy a guitar, buy a keyboard... it's not hard. But yea it takes time and work... the same time and work the artist put in to create the songs you are stealing as 50% of your "creation."
You can sing the James Bond theme. Heck you can play it on a recorder. Or how bout making up your own theme?
It's funny how so many people try to piggy back on others fame and talent and sucess. I'm really curious how people profit on cover songs in videos. I know to record a cover and release it you need a license. These licenses to do a cover are easy to get and cost less than $100 and you must pay a royalty for each cover song sale to the owner of the song... so what happens when a cover is on a video? Do these people get a lisence? Do the pay the owner of the song royalties on youtube views?