Comment I never expected to leave on a student paper:
"As far as I can tell, the concert you're writing about in this report never happened. The Royal Opera House is in London (UK), and their events schedule includes no mention of this concert on or around the date you provided. Additionally, I can find no trace of the existence of a "Graven Choral Society," none of your proofs of attendance refer to this concert, and Musica Antiqua Köln (which is a performing ensemble, not a composition) disbanded in 2007. Because of this, I can't give you credit for this paper."