Videomaker – Learn video production and editing, camera reviews › Forums › Specialty Topics › Legal Issues › Obtaining licenses and payment for them… › If you want to clear music
If you want to clear music for commercial use, go through a clearing agent. As paulears said, you can't just email people and ask to use music–you have to negotiate for rights, and you need to be sure you have negotiated the correct rights. If the song is well known, be prepared to pay dearly for the right to use it. That's why so many people use royalty-free music.