This isn't an oratorio in the Handelian sense, but a series of cantatas for various days from Christmas to Epiphany. Bach's music is loaded with treats: an echo aria for soprano and oboe; a "pastoral" sinfonia; bravura arias for tenor with flute and bass with trumpet; a giddy soprano-bass duet; a transporting lullaby for alto. Then there are the choruses, featuring the Monteverdi Choir at their best: exuberant full-orchestra choruses in parts one and three; a lilting triple-time chorus with horns in part four; the joyful skittering chorus in part five; and the triumphant opening and closing of part six (with spectacular trumpet solos). John Eliot Gardiner's direction is vigorous; the soloists, the best group you'll find on CD, include a terrific young Anne Sofie von Otter. --Matthew Westphal