This is a post I left on DVProfessionals. I wanted to include it here as an article about using copy written music and expound upon it:
I may use a song (rarely) in something personal or for fun but if it's going out into the world for profit then I use royalty free music. I use Digital Juice, Phoenix Clips, and others. Plus Magix has a good Sound Pools collection and you can make your own. Not worth taking the chance when so much cheap or free music is out there. ;-)
Also consider this. By using a popular song you can actually reduce the impact of your video. Most people already have visuals to a song in their head. Either the band, the music video, or their own imaginations visuals.
If you use a popular song the viewer may feel you are taking away from that. They may judge your video against the other one or simply tune it out because to them it doesn't fit. Deep inside they may not like the idea that their favorite song is changed visually. They may take a negative attitude like, "Oh, yet another video done to the tune of___"
If your video doesn't compliment the song or fit the way they think it should, based on an already preconceived idea of the song then they will not like your video.
No matter how good it is.
When you present a video with royalty free music they have never heard, the full impact of the video will be perceived. They are not comparing it to anything and your video will be what sticks with them if they ever hear that music again.
So ask yourself, do you want your video to be the one thousandth video done to "Stairway to Heaven", or do you want something original? Something that will carry the full impact of your work and efforts? Something that, when seen, will create and maintain visuals to that tune. Your visuals.
Just about every cool song, especially those from the 1970's has been made into a commercial. The visuals of that commercial are still in every ones head. They relate the song to that commercial even though they may not remember the product. So you are competing with that as well when you use popular songs.
If you use Michael Jacksons "Thriller" no one is going to remember your video, they will remember MJ's zombie makeup and doing the moonwalk so you've lost that impact for your video. After your video has played the last frame I guarantee you the conversation will be about Michael Jackson and that crazy video he did back in the 1980's. Your video and it's visuals will be lost on them. They won't remember it. They have already associated that song with MJ and other images.
So ask yourself, do you want to put all of your work and efforts into something that will carry the full impact of it's presentation, or ride on the popularity of another piece of work that will likely not support it?
You put a lot of time and effort into your video. Why spoil it with a popular song when there are many places to get good free music online? Or buy music cheap?
Create an original, not a knock off of someones other work. You are making videos to be seen and heard.
Not only is it illegal but it's devaluing your work. You are no longer the creator of a masterpiece, you now are just a copycat. Evermore your video will be known as "that video done to the tune of___", rather than your video. All yours. No one else's.
Even if someone has heard that royalty free piece it's likely they haven't associated it with any specific visuals. Most of your viewers probably have never heard it even if other video makers have. It may be well known in the industry but rarely heard by the general public or your family and friends. And even if they have they will not know where it came from.
So do yourself a favor and rethink using popular songs in your videos. Make a masterpiece you can call your own! Not only is it the right thing to do, it's the best thing to do.