When Jennifer Lopez sang Woody Guthrie’s “This Land Is Your Land” at Joe Biden's presidential inauguration in January of this year, it marked the latest use of Woody Guthrie's much-contested song. The history of "This Land Is Your Land," from the many versions of the song to the even more varied responses to it, raise important questions about what a national anthem is—and what it might do in the discordant politics and culture of the United States.