A ballad is a form of verse. It is often a story set to music. Ballads were popular in British and Irish poetry and music until the 19th century from the late medieval period. It was also used in Americas, Australia and North Africa. Many ballads were written and sold as single sheet broadsides. Poets and composers from the 18th century used this form. In this way, they produced lyrical ballads. In the later 19th century, ballads were slow form of popular love song. The term is now often used as synonymous with any love song, particularly the pop or rock "power ballad". 