The Birthdayy Partyy twins have come off their debut set at EDC Las Vegas with another throwback remix. “Hollaback Girl” by Gwen Stefani got a bassy makeover that listeners have been jumping all over since its release as a free download last week. Birthdayy Partyy go bananas with the 2004 hit that everyone remembers. In visiting this single, the brothers add yet another smash flip to their already impressive catalog. If you haven't ran through all their releases, it's about time for you to.