Marcel Pérès and Ensemble Organum's Messe de Noël reconstructs a liturgical Christmas mass from twelfth century sources associated with the school of Notre Dame. Most of the polyphony is taken from Wolfenbüttel 628, whereas the monophonic sections are derived from a number of manuscripts of the time; a couple of pieces of modern derivation taken from Solesmes editions are pressed into service. The scholarly component, indeed, is so rigorous that it has produced an album that is not very compelling. Only four singers are used, and while it is interesting to hear parallel counterpoint sung in evenly matched voices, the lack of weight in unison responses is difficult to get used to -- in practically every familiar instance a choir is used for such purposes, and four voices just don't cut it. While all but the Solesmes movements are taken from old manuscripts and a complete liturgy is produced, the individual pieces don't seem to hang together; the mass isn't the sum of its parts. The performances of Organum, too, seem underfed, although the sheer precision of the singing is very good. Compared to other later performances, this 1984 recording of the Ensemble Organum seems very chastened and unadventurous. But it comes very early in the group's recorded output and better things would be in store as time progressed. Messe de Noël is interesting mainly only as a curio, a relic of the time when this important group was first getting started.