Featuring two transfixing choral compositions written during vastly disruptive and painful historical events: Franz Josef Haydn’s Missa in Angustiis (Lord Nelson Mass), penned at a time when Haydn’s Austria was being invaded by the armies of Napoleon Bonaparte, and Ralph Vaughan Williams’ deeply moving Dona Nobis Pacem, composed between the two world wars and based predominantly on the Civil War poetry of Walt Whitman.