The liturgical music in England during this time underwent great changes, not the least of which was the shift between Latin and vernacular texts. At the outset of Tallis' career, the prevailing English style of Latin music followed the soaring treble-dominated textures of the previous century, as exemplified in the Eton Choirbook; his early Latin motets reflect this. But by the late 1540s, Archbishop Thomas Cranmer was working toward a standard liturgical practice, built around his Book of Common Prayer, that would finally replace the Sarum (English Latin) rite in 1559 with exclusively vernacular worship music. The reign of the Catholic "Bloody" Mary Tudor briefly interrupted this trajectory towards the vernacular with a militant resurgence of Catholic music in an older style; Tallis' Missa Puer natus and the motet Gaude gloriosa apparently date from this time. Stylistically, the church music of England over the second half of the century was yielding to the influence of the Continental imitative style, through the music of the transplanted Italian, Ferrabosco.
Through all these changes, Tallis appears to have retained a professional steadiness and respectability, making music and composing with grace and equanimity as his situation changed. His English-language settings range from simple treatments of the psalms to anthems (such as Hear the Voice and Prayer) to three complete settings of the Anglican Service; this music is commonly imbued with a somber and penitential mood. His Latin-texted pieces, whether following the stylish "modern" mode of pervasive imitation or not, demonstrate restraint and even tenderness. (One of the few exceptions, though, is his best-known work today, an over-the-top and still rather mysterious experiment in polychoral writing, the 40-voiced Spem in alium). Surprisingly little of Tallis' instrumental music survives, despite his over 50 years of professional organ playing.