Tucson Chamber Artists continues its 10th anniversary season this weekend with a concert that moves it one step closer to a Bach trifecta.

The professional chorus will perform Bach’s St. John Passion in three concerts this weekend, three years after it performed Bach’s monumental Mass in B minor. All that will be left is the St. Matthew Passion.

“I’m working up the courage to do the St. Matthew with the St. John,” said Eric Holtan, the group’s founder and music director. “The B minor Mass was the logical place to start.”

TCA had 26 vocalists on stage and 24 instrumentalists when it sang the B minor Mass in February 2011.

St. John Passion uses 24 vocalists in the chorus and two soloists. Seven members of the chorus sing the arias and the orchestra will have 18 instrumentalists, mostly on strings.

Then there’s the St. Matthew, which calls for a double chorus and double orchestra.

“The St. John is a complex work, but the St. Matthew is more complex with the double chorus factor,” Holtan said, which is why he put the St. Matthew at the end of the line.

The St. John Passion recounts the crucifixion of Christ as told by John, and Bach wrote it almost as if it were being performed as an opera. The piece is framed by dramatic choruses followed by recitatives, ariosos and arias sung with enough expressed drama to convey the story.

“It’s the closest thing to opera that Bach wrote,” Holtan said. “It’s navigating all that activity while you’re trying to tell the story. It is one of Bach’s most important works and it also is one of the most significant works of the whole cannon.”

University of Arizona musicologist John Brobeck said you won’t hear the St. John Passion often.

“It takes a lot of effort to mount the thing just because of the size of the performing force that is required,” said Brobeck, who years ago conducted the piece with the UA Collegium Musicum. “In terms of the difficulty of the choral writing and the solo writing and the length of the piece — it’s over two hours long — yeah, it really deserves to be called a monument.”

I cover music for the Arizona Daily Star.