The steel guitar originated in Hawaii, credited to Joseph Kekuku, who began sliding a piece of metal across the strings of a guitar. This 'slide' technique allows for smooth glissandi and microtonal 'whining' sounds. Unlike a standard guitar, it is played horizontally on the lap or on a stand. In the 1950s, the 'pedal steel guitar' was developed, adding foot pedals and knee levers that change the pitch of individual strings while playing. This made the instrument one of the most complex in the world, often called 'the guitar that's also a machine.' It is the defining sound of modern Country music and Hawaiian music.