Perform a search to discover who owns the rights to the music. The best way to accomplish this is through the U.S. Copyright office. The office is located in Washington D.C. and is open for visitors to perfrom searches of their records. If you are not in the D.C. area, you can perform an online search through their website (link in the "resources" section below), provided the records do not date back further than 1979. If the records are from 1978 or prior, the office can perform a manual search for you at a cost of $165 per hour with a two-hour minimum.
Write a letter to the copyright owner requesting permission to use the copyrighted music. Be clear and to the point in the letter. Indicate which song you want to use, the purpose for which you intend to use it and a request to use it free of charge. In addition, include either a separate form or an area on the letter that the owner can sign and acknowledge their permission to use their song. Finally, place a self-addressed, stamped return envelope in the package with your letter. Remember, the copyright owner has no obligation to allow you to use the music and no reply at all means they are not granting you permission.
Download or upload the song to your computer once you have obtained permission to use the music. Obtain the song through legal means. Just because you have permission to use the song does not mean that you can download it free of charge. Either purchase the .MP3 file legally through sites like Amazon, Rhapsody or eMusic.com, or upload the song to your computer from a CD that you have purchased.
Insert the music into your movie file using a video editing program. There are many different programs that allow you to do this. If you do not want to purchase one, Windows Movie Maker comes pre-installed on later versions of Windows. Simply select the "import media" option in the program you are using. It is either a separate button at the top of the screen or in the "file" menu.
Insert the music into the timeline of your movie file. This is the area at the bottom of the screen which displays the order of the movie clips. There should be an area underneath where you can drag the music into the section where you want it to play. For example, if you have four movie clips in your file and you want the music to play starting with the second clip, drag it to the music timeline underneath the second clip.
Save the project and burn it to a DVD. The easiest way to do this is by opening the file in Windows Media Player and selecting the "burn" option. Your DVD is now complete and available to use with the copyrighted music.