Or in the compact syntax

start =
  element SONG {
    element TITLE     { text },
    element COMPOSER  { personContent }+,
    element PRODUCER  { personContent }*,
    element PUBLISHER { text }?,
    element LENGTH    { text }?,
    element YEAR      { text }?,
    element ARTIST    { text }+
  }
personContent =
  element NAME {
    element GIVEN  { text },
    element FAMILY { text }
  }