Android: Can't Add MP3s

If you add MP3s to your Android phone and they are not getting picked up in your music player's library (stock, doubleTwist, Winamp, etc) then you need to clear the Media Storage database. Under settings go to the Manage Applications option, select the All option and click Media Storage. Click the Clear Data button and you are done. I am using MIUI Rom so the steps may be different, but the cause and solution should be universal to all Android versions.