On paper, the prospect of all three of William Byrd's Catholic Masses, given at a single sitting (on the penitential Oratory wooden chairs) was not an enticing one.

For all we admire the composer's courage in producing such works in the post- Reformation Protestant ascendancy, and however much academics proclaim the skill of their construction, as a total listening experiment they might run the risk of cancelling each other out.

But this was not the case in Saturday's remarkable and moving presentation from Ex Cathedra. Experience should have taught us by now to expect something enlightening and Midas-like in everything Jeffrey Skidmore touches, and this sequence of the Masses for Three, Four and Five Voices, interleaved with various motets, mined gold in the riches it conveyed.

The location was perfect, of course, Byrd's subtly-hewn lines rolling and dovetailing amidst the marble, enunciation from these adept choristers given just the right amount of edge without sounding contrived and obtrusive. And a subtle choreography transformed the trinity-like disposition of forces for the three-voice mass into a more solid phalanx for the subsequent two.

Skidmore's choristers sang with rich, eloquent tones, never forcing the listener's awareness of the composer's modest forays into word-painting and coping well with the demands of maintaining pitch in these unaccompanied canvases.

Just occasionally the physical demands told, but nothing detracted from the deep commitment and involvement of these performances.

Byrd probably imagined these works with single voices to each part. It is a huge tribute to the relationship between Skidmore and his singers that the effect of the music remained intimate and uncloyingly devotional.

Christopher Morley