There are two famous classical settings of the Catholic prayer "Ave Maria" (one by Schubert, one by Bach/Gounod), and neither of them was originally intended to be religious music. This is an arrangement of Schubert's song, which is officially titled "Ellens dritter Gesang" (Ellen's Third Song), part of 7 songs from Walter Scott's epic poem "The Lady of the Lake". The British cellist Sheku Kanneh-Mason performed this during the royal wedding of Prince Harry and Meghan Markle in 2018.