Find out who currently owns the copyright of the song you wish to buy the rights to use. You can pay someone at the U.S. Copyright office $165 an hour to search the information database for you, or you can appear in person and search the files yourself for free.
Search for contact information for the copyright owner. You might have to request contact through a third party, such as the copyright owner's agent or management company.
Contact the copyright owner, explaining to her that you would like to buy the copyright to her song. Tell her how you would like to use the song. If you are planning to re-record the song, you might consider sending her a sample so she can hear your version before deciding.
Negotiate terms with the copyright owner to purchase the rights to use his song. Make sure when drawing up the paperwork the terms are fair and you have the full amount of access to the song you requested. You will need a lawyer to draw up and file the paperwork for you. Plan to pay for legal fees and services.
Sign all necessary legal documentation, and pay the copyright owner the agreed amount designated in the contract.
Display all copyright ownership information properly when listing your version of the song on album covers or music scores.