Mobile device video recording sounds WAY too loud, easy fix?

I recently recorded some songs on video at a concert on both an iPod nano and regular camera, and although the video came out fine, since we were standing so close, the mic must have been overloaded on both devices, and when they are played, they are just so muffled and distorted because the music there was SO LOUD. Is there any way, hopefully easy, to reduce the sound, and possibly recover some of the music so it at least partially listen to-able? Thanks!