Thomas Weelkes's sacred music for the Anglican liturgy falls into two distinct categories: smaller-scale pieces for the 'half choir' at Chichester Cathedral (where he was Organist) and more ambitious works for the Chapel Royal where, it is thought, he was a 'Gentleman Extraordinary'. Accordingly, his ten services demonstrate the full range of this genre, from concise 'short' and verse settings to large-scale works such as the Fifth (in medio chori) and Ninth Services. The modest scope of the First Service indicates that it was almost certainly written for Chichester.

The Service is remarkable for the complexity of its musical cross-referencing both within and between its movements, while there are also similarities with the composer's Third Service ('for the organs in F fa ut'). Another unusual feature is the concluding 41-bar chorus in the Magnificat, which recalls the extended chorus writing in Byrd's seminal Second Service. The Wimborne part-books refer to the work being paired, as in several other services by Weelkes, with an anthem: Thou art my portion (Psalm 119:57), for which there are chorus parts to the words 'Blessed art thou, O Lord' (Psalm 119:12).