Thomas Tomkins (1572-1656) was an organist and member of the Chapel Royal at the turn of the seventeenth century. A pupil of William Byrd, he wrote in the established idioms of the era and compiled a large and varied output. His relatively late death places him well into the seventeenth century, at a time when musical fashions were changing and the Civil War was altering the course of British History. However, it is correct to describe him as ‘the last Elizabethan’, as his style remained conservative, as did the genres with which he worked and cultivated. ‘Musica Deo Sacra’ is supposed to have been supervised by his son Nathaniel, and collates much of Tomkins’ music not found in other sources. As such, it is a valuable resource for the material it contains, and is also a landmark in music publishing, in that it presents the first known printed organ book set in moveable type on two staves, an unrewarding process which seems to have caused considerable trouble for its printer, William Godbid. Even John Barnard in preparing his ‘First Book of Selected Church Musick’ (1641) did not go to the trouble of printing an organ part to supplement his vocal partbooks, instead providing his customers with a blank manuscript book into which the already ubiquitous organ parts could be copied by hand. As a result, Tomkins’ source as a whole contains a number of errors, but all of which can be corrected without distortion to the musical text, and the composer’s intention can be realised without too much difficulty. As the subtitle states, ‘Almighty God’ is set for the Communion service as found in the Book of Common Prayer. At the end of the service are given a number of collects, the rubrics for which read thus: “Collects to be said after the Offertory, when there is no Communion, every such day one or more; and the same may be said also, as often as occasion shall serve, after the Collects either of Morning or Evening Prayer, Communion, or Litany, by the discretion of the Minister.” Tomkins therefore sets the fifth of these, perhaps in homage to his teacher William Byrd who set the fourth, namely ‘Prevent us, O Lord, in all our doings’. Indeed, the two settings share a number of similarities, including the double alto part typical of music of the period. The setting by Tomkins is suitable also as an anthem at Matins or Evensong.