A name of a song-although very vague in description?

Hi its a bit of a bizarre question and I'm sure I'd like it if you guys could help me- my late father was put to rest on friday-and one of the tunes played included lyrics 'angels' I know its not Robbie Williams, I'm thinking it might be more on the opera type of song, I am at a loss as to the song. A bit vague but its such a beautiful song, I didnt even get the artist any genuine help would be appreciated. many thanks