Holly Brook Hafermann (born February 23, 1986), who goes by the stage name Skylar Grey, is an American singer-songwriter from Mazomanie, Wisconsin, United States. In 2004, under the moniker Holly Brook, at the age of 17, she signed a publishing deal with Universal Music Publishing Group and a recording contract with American rock band Linkin Park’s Warner Bros.

Records’ label imprint, Machine Shop Recordings. She would later release her debut album, "Like Blood Like Honey", under the labels in 2006.In 2010, she co-wrote Eminem and Rihanna's hit single "Love the Way You Lie", alongside British record producer Alex da Kid, who subsequently signed her to his label imprint, KIDinaKORNER.

Grey is perhaps best known as a guest vocalist on several hit singles, including Fort Minor's "Where'd You Go", P. Diddy's "Coming Home", Dr. Dre's "I Need a Doctor", T.I.'s "New National Anthem" and more.

Grey's second album, "Don't Look Down", was released in July 2013. The album was preceded by four singles, "C'mon Let Me Ride" (featuring Eminem), "Final Warning", "Wear Me Out" and "White Suburban".As a child, Grey performed professionally in a folk duo with her mother, called Generations Together, with producer and engineer Randy Green, they independently produced three albums, Dream Maker, Lift Me, and Millennial Child / Waiting for You.

Grey started her first band at the age of 15, after 'sneaking' into bars and working with jazz musicians Jeff Eckles, Tim Whalen and Leo Sidran in Madison, Wisconsin. In 2003, Grey moved to Los Angeles and recorded a demo under the alias Holly Brook, which would be her stage name for several years.

This demo led to her being signed in the fall of 2004 by Linkin Park guitarist Brad Delson, to the band's vanity label, Machine Shop Recordings, at the age of 18.