When you have to study, but you're too busy making mashups You can grab it for free now, enjoy! FREE DOWNLOAD. A mashup featuring Gwen Stefani (Hollaback Girl) on the My Humps track by Black Eyed Peas. Mixed by Pytski. Hollaback Girl by Gwen Stefani vs. Yoncé by Beyoncé. Download here: https:// houdini-connections.co.uk Twitter.