Bell X1 are an Irish rock band from County Kildare in Ireland. They have thus far released four critically-acclaimed albums in Ireland, and in recent years have gained success in the United States, where their music has been used on popular television shows such as The O.C. and Grey's Anatomy. Their third album, Flock, which was previously only released in Ireland and later in the UK, received a North American release in February 2008. Their fourth album, Blue Lights on the Runway was released in Ireland on 20 February 2009 and had a US release on 3 March 2009.