This is another situation where you want to identify the problem before starting to treat it. Vibration damper may help, especially if what you are hearing is resonance in the sheet metal or trim panel or a rattle energized by that resonance. Assuming it really is a rattle, see if you can stop it by pressing on the trim panel. If you can, isolating the trim panel from the inner skin using closed cell foam or something similar will probably do the trick. If it's an actuator rod, inside the door, sliding some vinyl tubing over the rod often works. Instead of relying on music that occasionally causes the noise, use test tones and find the frequency that makes it easily repeatable.