MUSIC : Decorating Bach’s B-Minor Mass

Except for the music of Bach, the recent “historical practice” movement in music has been beneficial in at least one way. We now know that singers and instrumentalists of the baroque and classical periods didn’t restrict themselves to playing only what was written in the score.

They would ornament--or embellish--musical lines by adding trills or other well-known figurations with arcane names such as appagiaturas, mordents, inverted mordents and the like. The idea was to heighten expressivity and musicality and provide an outlet for individual artistic improvisation.

Bach’s music as heard today has remained largely untouched by these insights. But for a change of pace, William Hall will lead the Master Chorale of Orange County in an ornamented version of Bach’s B-minor Mass on Sunday at the Orange County Performing Arts Center in Costa Mesa.

“What I try to do is take Bach’s ornaments and apply them to other arias where he didn’t write them out,” Hall said.

“But every time I do it, I do it differently. I write the embellishments all out, then I experiment with the solo voices I have.

“The feeling of the soloists at the first rehearsal is, ‘How dare you do something like this!’ Then they get into the spirit of it and begin making suggestions: ‘This seems more natural if you do it this way.’ It’s a loving give-and-take from then on.”

Bach’s third son--Carl Philip Emanuel--actually wrote in a musical treatise published in 1715 that “without (ornaments) the best melody is empty and ineffective, the clearest content clouded. (Yet) a prodigal use of embellishments must be avoided. Regard them as spices which may ruin the best dish.”

In time, the excesses C.P.E. Bach warned against prevailed, and to discourage the practice, musicians eventually would be taught to revere the printed page. By the time of Beethoven, embellishments were simply not an option for the players.

Eventually, this attitude would be applied to the earlier music that had been composed with the expectation that the artists would add their own ideas, and so what was a reformation turned into a complete misunderstanding of how the earlier music was conceived.

It is only with the historical practice movement that we have begun to return to the original idea. These days, performances of Handel’s “Messiah,” for instance, often can be heard with the vocal soloists embellishing their lines.

“I started to ornament the ‘Messiah’ 30 years ago, even the chorus and orchestra parts,” Hall said. “Today a zillion conductors are doing old instrument versions and very embellished performances. It makes the ‘Messiah’ come alive.”

And maybe the B-minor Mass too.

What: William Hall will lead the Master Chorale of Orange County in Bach’s Mass in B minor.

When: Sunday, March 15, at 7:30 p.m.

Where: Orange County Performing Arts Center, 600 Town Center Drive, Costa Mesa.

Whereabouts: San Diego (405) Freeway to Bristol Street exit. North to Town Center Drive. (Center is one block east of South Coast Plaza.)

Wherewithal: $12 to $35.

Where to Call: (714) 556-6262.