Folk songs are songs of often anonymous origin (or are public domain) that are transmitted orally. They are frequently a major aspect of national or cultural identity. Art songs often approach the status of folk songs when people forget who the author was. Folk songs are also frequently transmitted non-orally (that is, as sheet music), especially in the modern era. Folk songs exist in almost every culture. The German term Volkslied was coined in the late 18th century, in the process of collecting older songs and writing new ones. Popular songs may eventually become folk songs by the same process of detachment from their source. Folk songs are more or less in the public domain by definition, though there are many folk song entertainers who publish and record copyrighted original material. This tradition led also to the singer-songwriter style of performing, where an artist has written confessional poetry or personal statements and sings them set to music, most often with guitar accompaniment.
