Leave it to the Moravians to stop traffic for a church service in downtown Bethlehem.

The occasion was the "Moravian College Christmas Vespers" at Central Moravian Church.

Those standing in sub-freezing temperatures on the steep, cold steps outside the doors of the historic church (built 1803-06) craned their heads to see which impatient driver was blowing a horn in the Main and Church streets gridlock.

"Nothing says Christmas like a honking car horn," cracked one online onlooker. The blaring horn almost drowned out the trombone choir playing from the church belfry.

Bethlehem, founded in 1741, held its first candlelight service in 1756. USA Today named Central Moravian "one of the nation's 10 great places to reflect on Christmas." The Moravian Vespers (Dec. 6, 7, 8, 13, 14, 15) is one of the "toughest tickets in town" during holidays in the Christmas City.

Central is filed to its capacity of 850 each night, according to Michael P. Wilson, director of Public Relations and Marketing, Moravian College.

"We don't sell tickets," Wilson points out. "The college invites students and their families, faculty, staff and donors. We then provide tickets to alumni and members of the public who request tickets until we reach capacity."

My ticket was courtesy of my son, Elias, a Moravian College junior. I previously attended the Vespers as a journalist. This year, I was dad.

With Moravian promptness, doors opened as stated at 7:15 p.m., and the service began at 7:30 p.m. with "Tacuit in praespio," a serious-sounding but whimsical work by Larry Lipkis, composer in residence, Moravian College, sung in Latin by the Moravian College Women's Chorus, directed by Eduardo Azzati:

"Text message not thy neighbor nor read any messages thou receivest, nor shalt thou use Twitter ...

"Now, silently, let us celebrate the miracle of that wondrous winter night."

The 19-voice choir concluded, gloved hands to lips, whispering, "Shhh."

As a dozen lights flickered on each wall and the ultimate Bethlehem star shone behind the altar, some of the Lehigh Valley's top musicians continued a tradition that began with trombone-toting Moravian farmers, continued with J. Fred Wolle, founder of the Bach Choir of Bethlehem, and on through five decades of Vespers at Central.

The music department was out in force: Moravian College Brass Ensemble, Moravian College Flute Troupe, Moravian College Guitar Ensemble, Moravian College Wind Trio and the 81-voice Moravian Choir, conducted by Paula Ring Zerkle.

The choir - men in tuxedoes and women in black dresses - sang from the back loft until "Louez le Seigneur!," a Cameroon processional with two-by-two rhythmic-stepping and gently-swaying entrance in the aisles.

The hour and one-half concert included 27 pieces: classical ("Tu pauperum refugium," Josquin des Prez, circa 1450-1521) to contemporary ("Love Is the Key," Zebulon M. Highben, born 1979) to traditional carols ("The Twelve Days of Christmas"), some with the audience singing along.

The theme, "Gratitude and Love," Jennika M. Borger, chaplain, Moravian College, explained, demonstrates "that we are better together than we are apart" and is intended "to soften our hearts to give priorities to justice and to live lives of love."

The program built to an emotional peak. The lights dimmed. Lit beeswax candles, carried on trays, were handed out, leading up to "Morning Star" (soloist Kayden Alexander Stocker, Dec. 7).

The Moravians know how to do drama. And they do it well.

Gridlock is long forgotten.