The three unaccompanied masses Byrd composed during the 1590s are masterpieces of late Elizabethan polyphony. The Mass for Three Voices (1593-1594), like its companions for four and five voices, is a setting of the sections of the Ordinary: Kyrie, Gloria, Credo, Sanctus, and Agnus Dei. Byrd wrote the work for use by Catholics during a period when celebration of the mass was strictly forbidden. Still, Catholics (or recusants, as they were then known in England), continued to perform their central act of worship under cover of strict secrecy. Byrd's masses were therefore composed for practical use and conceived expressly for small-scale, furtive performances. After moving from London to Essex in 1593, Byrd himself may have been involved in such acts of worship at the nearby home of Sir John Petre, a notable member of the Catholic community and a friend and patron of the composer. The Mass for Three Voices is the briefest of Byrd's three masses, almost certainly because the opportunities for passing thematic material from one voice to another are restricted by such a small number of parts. There is no evidence that Byrd had a particular vocal disposition in mind, and the mass works as well for soprano, alto, and tenor as it does for alto, tenor, and bass, or even tenor, baritone, and bass. Such flexibility is obviously logical, given the conditions under which the work was originally intended to be sung. In each of his masses, Byrd was careful not to make the vocal writing too complex; the scoring in the present work is mainly syllabic, with little complex melismatic writing. Still, within such apparent austerity, Byrd produces many wonderfully expressive moments, with key passages in the text highlighted to great effect.