Popular songs or phonograph records and radio, though all other mass media that have audio capability are involved. The popularity of popular songs is inferred from commercially significant sales of recordings, ratings of stations and networks that play popular songs, and ticket sales for concerts by the recording artists. A popular song becomes a modern folk song when members of the public who learn to sing it from the recorded version teach their version to others. Popular songs may be called pop songs for short, although pop songs or pop music may instead be considered a more commercially popular genre of popular music as a whole.
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, if not all, culture(s). For more on folk songs, see Folk music.