Graham Gordon Ramsay composed his Requiem as a response to human loss, his own aging and, as he said in a program note, “the tumultuous world of 2025.” Sarah Kirkland Snider’s Mass for the Endangered focuses on the rapid extinction of non-human species and humanity’s role in it. A virtuoso performance of both works end given by the Emmanuel Choir Sunday afternoon, emphasizing music’s ability to transmit the beauty and energy of life while providing a vehicle for grief.