How badly does Philadelphia need a Bach festival? Bad enough that on a frigid Sunday afternoon at the Presbyterian Church of Chestnut Hill, the line was out the door, the pews were packed, and folding chairs accommodated all who wanted to hear the program - and not thanks to holiday warhorses.

The occasion was the first joint concert of the Bach Festival of Philadelphia and the Choral Arts Society in a program of Bach Christmas cantatas (not necessarily the best-known ones), the audience size illustrating the power of artistic consolidation in what promise to be hard times ahead.

The festival has tried out a number of identities: Past music director Jonathan Sternberg represented the time-honored postwar tradition of Central Europe, while new music director Matthew Glandorf favors the authentic-instrument camp, most audibly in the current Bach Festival Orchestra. Such transitions take time to jell; a more telling artistic litmus test will be the May 9 performance of Bach's

Mass in B minor

.

The Sunday concert wasn't exactly blessed with beginner's luck. Performances were tentative more often than not, and though seasoned ears could tell what Glandorf was after, the interpretive point of view needs considerable focusing. In all fairness, the repertoire was challenging for many reasons: The second section of the

Christmas Oratorio

isn't the easiest sell due to its meditative nature, and the opening chorus of "Wachet auf, Ruft uns die Stimme" is typical of the challenges of Bach's cantatas, which best respond to a specialist sensibility if only because Bach felt freer to experiment and run with the quirkier areas of his muse.

By no means was it beyond the grasp of the Choral Arts Society - the performance was in fact valiant - but a greater level of authority isn't too much to ask from any Bach festival.

The guest vocal soloists could do the job, but were often far from commanding the music in a way that one reasonably expects from a specialist festival like this. Tenor David Price projected a lively sense of the German text, but the voice wasn't always the willing servant of his mind. Mezzo-soprano Jenifer Smith had a lovely sound - when she could be heard, which was about half the time. Singers that more consistently and convincingly assembled all moving parts were soprano Laura Heimes and baritone Brian Ming Chu.

The authentic-instrument Bach Festival Orchestra needs the most work. It often failed the distinctive wind writing in the

Christmas Oratorio

section. And though in sturdier form for

Concerto in A (BWV 1055)

with oboe d'amore soloist Geoffrey Burgess, the performance felt more like a run-through than a serious, considered look at the music. There are other baroque music groups in town. Maybe further consolidation is in order?

Contact music critic David Patrick Stearns at dstearns@phillynews.com.