Musically they're things of great beauty. Tallis' intent was for them to be sung not consecutively as they're sung below but separated by the sung responsorium In monte Oliveti (which is why Tallis has set them in different modes). Each motet's various sections are delineated by Hebrew letters that Tallis has set almost as though they were consort music while the verses themselves are full of subtle musical effects to heighten the effect such as cumulative repetition and the almost antiphonal way in which Tallis sets off one voice against the rest. Whether you take them individually or together they're beautifully designed pieces of musical architecture that are also profound spriritual and of whose purpose – a plea by Tallis, a Catholic in a Protestant country that his homeland return to the Catholic faith 'Ierusalem, Ierusalem, convertere ad Dominum Deum tuum' (Jerusalem, Jerusalem, return unto the Lord thy God.) there can be no doubt.