Coldplay are a British rock band formed in 1996 by lead vocalist Chris Martin and lead guitarist Jonny Buckland at University College London (UCL). Martin once proclaimed the band's music as "limestone rock" in comparison to "hard rock". The band's music has been called "meditative" and "blue romantic"; it "[reflects] on their emotions" and Martin "endlessly examine[s] his feelings". Along with Martin (piano), and Buckland (guitar), the band also includes Guy Berryman (Bass), and Will Champion (drums). Despite their worldwide popularity, the band has remained protective of how their music is used in the media, refusing its use for product endorsements. They are named after a British psychology book called Child's Reflections, Cold Play.