Music holds an important place in Irish tradition. Prior to widespread literacy, traditional songs and ballads were an important vehicle for the oral history tradition. After the Great Famine in the nineteenth century, song was one way to maintain the use of Gaelic and pass on history and lore to new generations of the Irish diaspora. The Celtic harp—an ancient instrument associated with the Gaelic ruling class— remains an important national symbol in the Republic of Ireland. The Celtic harp on a green field (the Green Flag) was first used on a flag as a symbol of Ireland during the 1641 Rebellion. It was flown alongside the Irish tricolor during the 1916 Rising.