"Crystalised" is the first single by The xx, released from their self-titled debut album. The single was first released in the UK on 27 April 2009 by Vinyl and on 25 November 2009 by Digital download and then again on 11 October 2010. It has been used in numerous advertisements and TV shows and has over 26 million hits on YouTube as of June 2011. It was sampled in the song "Less Than Zero" by K.Flay and covered by Gorillaz whose version was included in the advertisement for Grey's Anatomy in late 2010. In 2013, it was covered and released as a single by Martina Topley-Bird, Mark Lanegan, and Warpaint.