Music review: Angels Unawares by Sir James MacMillan (Cadogan Hall); Allegri Miserere and other works (Barbican Hall)

THE title of Sir James MacMillan’s oratorio Angels Unawares is taken from Hebrews 13.2. “Be not forgetful to entertain angels, for some have entertained angels unawares.” The 70-minute work, for choir, tenor, and soprano soloists, with strings, ti...