Contrary to common misconception that the piece was composed to accompany the traditional Roman Catholic prayer Ave Maria, Franz Schubert originally composed the song as one of seven set to the epic poem The Lady of the Lake. In the poem, a woman named Ellen Douglas is singing a prayer to Virgin Mary before Roderick Dhu goes into battle in rebellion against King James. The opening words of the song Ave Maria, combined with the subsequent popularity of the melody set to the traditional prayer caused this generalization.
This piece has also been featured in many movies and tv shows including: The Hangover III, The Intouchables, Glee, Psyche, 28 Days Later... the list goes on and on to a total of 210 titles on IMBD.
Ave Maria (Op. 52, No. 6 - Ellen's Gesang III) - Composed by Franz Schubert
Performed by Mirusia Louwerse
And as mentioned earlier, my favorite instrumental version would be Franz Liszt's arrangement, performed below by Andre Hamelin