Britney Spears is not the only famous singer to rely on Auto-Tune to make them sound good.  But until I listened to this leaked version of Britney's "Alien" I had no idea exactly how much of a difference Auto-Tuning makes.

An unaltered studio session voice track of "Alien" has been leaked online.  It's from Spears' 2013 album Britney Jean.

You can listen to both cuts below and decide for yourself.  The first cut below is the finished product.  The second cut is the "unedited" version.  Give them both a listen and tell us what you think.