Question: 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?
Sentence (from "O Sanctissima"): The tune is often called "Sicilian Mariners Hymn" or similar titles, referring to the seafarers' nightly invocation of Mary as their maternal protector: Our Lady, Star of the Sea.
Relevant evidence: No