 " Ave Maria " is a ballad that runs for 3 minutes and 42 seconds . The Village Voice 's Nana Ekua Brew @-@ Hammond described the song as being " opera @-@ tinted " . According to the sheet music published by EMI Music Publishing , it is written in the key of C Major with a slow tempo of 75 beats per minute and it is set in common time . The song samples Franz Schubert 's " Ave Maria " , however as noted by Leah Greenblatt of Entertainment Weekly , even though it " does riff on the classic aria , it 's not an actual cover " . The main instruments in " Ave Maria " include a piano and strings . Throughout the song , Knowles ' voice shows restraint as she sings in a lower register with an operatic soprano that gives her more vocal power , as commented by Jennifer Vineyard of MTV News . Her vocal range spans from the music note of B3 to E5 . Lyrically , " Ave Maria " is about being surrounded by friends but still feeling alone , as conveyed by the lines , " How can the silence seem so loud ? " and " There 's only us when the lights go down " . This view was echoed by Joey Guerra of the Houston Chronicle , who wrote that the song weaves " a vivid tale of a desperate woman " . 
