It’s hard to fathom what the Boston Pops gets itself into with its annual Holiday Pops marathon, which takes up most of December at Symphony Hall. Last year, this orchestra played essentially the same program, with a few tweaks for family shows, 42 times in a bit less than three weeks. Santa Claus attended every concert.

Boston audiences have come to expect that certain items will appear on the bill: Leroy Anderson’s “Sleigh Ride,” for example, and a dramatic reading of Clement Clarke Moore’s “A Visit From St. Nicholas.” The best of them, at least for wit, is David Chase’s monstrously inventive arrangement of “The 12 Days of Christmas,” which quotes Beethoven’s Fifth Symphony, “Oklahoma!” and “Bohemian Rhapsody.” Sung with gusto, usually by the Tanglewood Festival Chorus, it surprises every time you hear it.

Lockhart conducts nearly all the beloved Holiday Pops concerts throughout December.Credit…Jillian Freyer for The New York Times

Then again, the whole Holiday Pops enterprise is something of a surprise. In the performances last December, the musicians of the Pops — essentially the Boston Symphony Orchestra without most of its principals — never seemed to look bored, and some had enough ho, ho, ho in them to wear a seasonal hat or even dance onstage. Musical standards remained admirably high.