Unlike Handel’s “Messiah,” Bach’s “Christmas Oratorio” has never been a Boston holiday tradition. Of course, it didn’t start out as a single performance piece in its home town of Leipzig. Bach composed (or recomposed — a lot of recycling was involved) the oratorio in 1734, and the six cantatas that make it up were first presented individually in the churches of St. Thomas and St. Nicholas between Christmas Day and Epiphany of 1734-35. The whole runs some 2½ hours, significantly longer than “Messiah,” and it’s a test of the musicians’ expressiveness. The welcome performance offered by Emmanuel Music Saturday at Emmanuel Church, under its artistic director, Ryan Turner, did not fail that test, but it didn’t pass with flying colors.
The narrative thread of the “Christmas Oratorio” is the Evangelist’s recital, from the Gospels, of Christ’s nativity, in an upbeat version with Herod’s slaughter of the innocents omitted. On that thread Bach and his librettist (probably German poet Christian Friedrich Henrici) strung recitatives, arias, choruses, and chorales, these last mostly settings of hymn tunes like “Vom Himmel hoch” and (familiar from Bach’s “St. Matthew Passion”) “O Haupt voll Blut und Wunden.” The nonbiblical texts are more personal than the libretto of “Messiah” (which is all from the Bible); the music is not as operatic as Handel’s. The vocal soloists need to pour their hearts out; the instrumentalists have to swing.