Nigel Short’s virtuoso chamber choir Tenebrae takes “passion and precision” as its motto, and both qualities will be in play in this beautifully-conceived sequence of Easter music from across cultures and centuries. Tonight, as part of the St Martin’s Easter Festival, they focus on the tragedy at the heart of the Easter story; songs of sorrow and quiet hope that range from the raw, ringing passion of Sir James MacMillan’s Miserere to the intense beauty of the music that William Byrd wrote for secret worship in a time of religious repression. Music that soothes the spirit even as it wrings the heart.