Short and usually simple piece of music for voice, with or without instrumental accompaniment. Folk songstraditional songs without a known composer transmitted orally rather than in written formhave existed for millennia but have left few traces in ancient sources. Virtually all known preliterate societies have a repertory of songs. Folk songs often accompany religious ceremonies, dancing, labour, or courting; they may tell stories or express emotions; the music follows obvious conventions and is often repetitive. Songs written by a particular composer or poet generally are more sophisticated and are not attached to activities. In the West the continuous tradition of secular art songs began with the troubadours, trouvères, and minnesingers of the 12th–13th centuries. Polyphonic songs, originating in the motet, began to appear in the 13th century. Composers of the 14th century produced a great body of polyphonic songs in the formes fixes. Later the Italian madrigal became the most distinguished genre. Notated accompaniments to solo songs appeared in the 16th century. The Romantic movement made the 19th century a golden age for the art song, notably the German lied. In the 20th century the popular song displaced the more cultivated art song, and popular music is today synonymous with popular song.