The tune of "O Sanctissima" has been notably reused in the first half of a American civil rights anthem that is most commonly attributed as having descended lyrically from what hymn?
O Sanctissima: "O Sanctissima " (O most holy) is a Roman Catholic hymn in Latin, seeking the prayers of the Blessed Virgin Mary, and often sung in various languages on her feast days. O Sanctissima:  The tune has been notably reused for the German Christmas carol "O du fröhliche" (O, how joyful), the English recessional hymn "Lord, Dismiss Us With Thy Blessing", and the first half of the American civil rights anthem "We Shall Overcome".
i don't know