This comes from last year's BBC Radio 3 series ''The Octave of the Nativity''. And the outstanding interest of the recording—apparently it's the first professional recording ever to be made in the Sistine Chapel—lies in its most successful recreation of the whole atmosphere of an early seventeenth-century Papal household liturgical celebration. The placing of the voices has been carefully studied, with the 'priest' at the far end, the 'clerics of the Papal household' lining the walls, as if in choir, and the polyphonic singers grouped in their special cantoria. One listens as if one were standing in the centre of the ante-chapel, where, until comparatively recently, visitors might still stand on such occasions, and listen to the Sistine Choir.
The overall effect is startlingly convincing: indeed, one is only shaken out of the illusion that it's 'for real' when the Sanctus of Soriano's double-choir arrangement of Palestrina's famous Missa Papae Marcelli leads without a break into the Benedictus—that is, without the customary moment of hush, the sound of the sanctuary bell and the jingle of thurible chains. Had it actually been 'for real' there would probably also have been less perfection of dovetailing between the chant items and the polyphony, with carefully matching tonalities that made the whole performance a thing of great beauty and unity. Some ingenuity was required to tackle the acoustical problems of the polyphonic singers, confined to their little opera-box cantoria. Don't expect perfection here: only a very fair compromise and some glorious authentic echoes mounting up to Michelangelo's ceiling. The chant items were selected, as was fitting, from those dignified but gorgeously corrupt contemporary versions, and are performed quite robustly. Though, if 'authenticity' was really the ultimate aim they could have sounded rougher, more extrovert and with a stronger accentual pull.'