Continuing a tradition that dates to 1999, the Island Community Chorus takes to the stage of the Old Whaling Church on Dec. 1 and 2 to open the Christmas season with its 20th annual holiday concert.

Led by artistic director Peter Boak and with accompanist L. Garrett Brown at the piano, the chorus will sing a program of sacred and secular pieces in English, Latin and Hebrew. Performances are at 7:30 p.m. Saturday and 3 p.m. Sunday, and both shows will be followed by a reception downstairs in the Baylies Room featuring treats prepared by members of the choir.

“It’s almost the opposite of singing for your supper,” said Mr. Boak. “This weekend we’ll sing for you, and then afterwards, we’ll feed you.”

A centerpiece of this year’s program is the six-movement Magnificat attributed to Giovanni Battista Pergolesi, but now believed by most scholars to have been composed by Pergolesi’s teacher, Francesco Durante (1684-1755). The Latin text, known as the canticle of Mary, has been set to music by composers from the Renaissance to the current day, from Vivaldi and J.S. Bach to Rachmaninoff, John Rutter and Ralph Vaughan Williams. Its exultant passages of praise recall the power of such choral classics as Handel’s Messiah.

Around this centerpiece, Mr. Boak and the choir have built a varied program that includes such seasonal favorites as settings of Here We Come A-Caroling, O Little Town of Bethlehem and an arrangement of We Three Kings in 5/4 time that cleverly recalls Dave Brubeck’s jazz favorite, Take Five.

The concert also includes Hanerot Halalu, an arrangement of a song for Hanukkah performed in Hebrew, and Alleluia, a hauntingly reverent a cappella composition by contemporary composer Ralph Manuel.

In addition to Mr. Brown at the Steinway, instrumentalists accompanying the chorus this weekend will include Rebecca Laird on violin, Molly Conole on flute and Steve Tully on saxophone.

The Island Community Chorus has been meeting weekly since early September to rehearse for these concerts. Admission to each of this weekend’s performances is a suggested donation of $15 at the door.