Bach's 200 existing cantatas (100 more have been lost) represent one of music history's most remarkable achievements. The first volume in Erato's ambitious but much-needed traversal of the complete canon contains nine cantatas from Bach's early career. Except for "Christ lag in Todesbanden," these are lesser-known works, yet that doesn't mean they are of lesser quality. Here are some of Bach's most compelling choruses, accompanied by colorful and ingenious instrumental writing. Highlights abound, including the appendices that reproduce Bach's revised versions of cantatas 4 and 21. The choral singing is excellent: sensitive and agile, with unforced tone. Of course, there's Barbara Schlick's fluttery vibrato and occasional shrillness and tenor Guy de Mey's emphasis on "prettiness" over textual understanding. But from the very beginning of BWV 21 we hear confident, well-prepared music-making that carries throughout the recording. Perhaps most importantly--and largely due to Koopman's even-handed, purposeful direction--everything, including the sonic ambience, feels and sounds in proportion: a feature that bodes well for the whole series and makes this an excellent reference set. --David Vernier