''The Pillars of Eternity'' is the title of The Sixteen's third anthology of pieces from the Eton Choirbook (Vols. 1 and 2 were reviewed in April 1992) in an immense and praiseworthy project that will eventually reach a total of six such compilations. Even this will not give us a complete view of the contents of this extraordinary early-sixteenth-century manuscript, but the pieces have at least been selected to give us a good idea of the range of its repertory. The title is taken from the final verse of Edmund Spenser's The Fairy Queen by which JM (adviser to the project) draws attention to the durability of many of the tenets of faith expressed in the texts of these motets; the lasting appeal of the music has been proved by the success of this group's previous two discs in the series. It is not easy music, however, either to perform or to listen to, as several of the more extraordinary items in this compilation confirm.
The disc opens with Richard Davy's O Domine caeli, a vast and complex work lasting just over a quarter of an hour in performance, but apparently composed within a single day at Magdalen College, Oxford. The sheer length and substance of this motet are phenomenal, and even though its structure is articulated in the usual manner in this repertory through contrasts of vocal scoring, the interpretation of the whole is highly elusive. Schubert may have had his ''divine longueurs'', but this piece is just that: divine and long. It goes on and on in the most exalted, but perhaps inconsequential manner until its final resounding ''Amen''. What should a choir do with it except sing it as well as possible in terms of ensemble and intonation, as The Sixteen certainly do, and let the glorious sounds wash over the dumbfounded listener?
If this piece is somewhat perplexing, still more so is Robert Wilkinson's Credo in Deum / Jesus autem, a 13-voice canon in which the individual voice parts represent Jesus and the 12 disciples. JM aptly describes the net effect as ''harmonious chaos'', which it surely is, although, in common with all multi-voiced works of this period, it is harmonically static in a way that should delight minimalist fans. Symbolism is also the key to the structure of Wilkinson's setting of the Salve regina—the nine voice parts each representing a designated rank in the nine-fold hierarchy of angels. This is vintage Eton Choirbook, the composer pitting the full and sonorous directness of the tutti acclamations against the flights of fantasy in the solo sections, and, perhaps for this reason, the interpretation is 100 per cent secure and brilliant, while elsewhere on this disc The Sixteen sound less convincing— probably because they were less convinced. Still, this is another must, and not just a curiosity, for any self-respecting collection of renaissance polyphony.'