Welcome to 15Rock countdown, formerly the Dozen Rock Videos Countdown.   History: 07.24.2007-12.16.2007: Dozen Rock Videos Countdown. 12.17.2007-present: 15Rock.    The videos/songs contained here are from the rock, alternative, metal, and indie categories. There is a daily flashback video, which usually comes from the rock/alternative genre and often from the same artist/band that gets their world premiere.    This countdown was established on July