According to Luke's biblical account, there was music at the first Christmas, when heavenly angels arrived to sing Jesus' praises while the infant was dressed in swaddling clothes, lying in a manger.

In the centuries since, music has remained an important element of Christmas celebrations.

And, for better or worse, holiday music playing in stores has become an important part of retailers' plans to entice you to buy more presents.

As business schools across the country turn to studies of consumer behavior, entrepreneurs of tomorrow have learned that when you add music to the retail experience, more products are purchased.

It's simple, when you think about it: Getting into the holiday spirit, to businesses, means getting into the shopping spirit.

One of the most unsettling things about retail music is that most shoppers aren't even aware that they're being controlled.

That's by design, says Kurt Mortensen, a Provo, Utah-based author who has spent two decades researching subconscious triggers and how they affect our behavior.

"For the use of music to be effective, customers can't really be aware of it," he says. "The music should not be overpowering; rather, it should merely be an atmospheric presence."

The proof of this theory is in the aisles.

"In department stores, shoppers who are exposed to music shop 18 percent longer and make 17 percent more purchases than (in) non-music stores," says Mortensen, who teaches marketing classes at Brigham Young University. "There are even rhythms, pitches and styles of music that are best for different shoppers. Grocery shoppers respond best to slow tempos. Fast-food restaurants need a higher number of beats per minute."

Several recent studies confirm that music, when it fits the context, influences buying decisions, says Katie Liljenquist, an assistant professor at BYU's Marriott School of Management. She cited a recent study reporting that playing classical music, vs. Top 40 pop, in a wine shop increased purchases.

Background music has an impact on how much consumers buy during the holidays, by evoking positive emotions, says Seth Rabinowitz, a partner at Silicon Associates, a Los Angeles consulting firm. "Faster-pace music would logically tend to promote more impulsive purchases, while slower music fosters a more contemplative, planned, stay-a-while feeling."

Christmas music can help people remember a simpler, less hectic time — even if things were never really simpler or less hectic, says Michael Paoletta, an executive producer at Comma, a national firm based in Chicago that creates original music for films, the Web and TV commercials. "The classic holiday songs are comforting, like hearing from an old friend,"he says.

In some cases, though, this type of music marketing can backfire. Some shoppers might have their own form of Christmas blues, and hearing endless rounds of holiday tunes could trigger bad memories, leading to less-satisfying times at the mall and fewer purchases.

The never-ending rounds of holiday music bedevil Massachusetts-based marketing expert Shel Horowitz. It's "the barrage of repetition, the feeling that I can't escape," says Horowitz, the author of six marketing books. "It's the really commercial ones that I find intrusive: 'Jingle Bells,' 'Rudolph.' They're loud and not very musical, and they tend to emphasize the less spiritual aspects of Christmas — and you hear them sometimes five times per day each, if you're going on a lot of errands."

Besides backfiring, music can be culturally ruinous, according to "Must we have Muzak wherever we go?," a 2008 study by Alan Bradshaw of the University of London and Morris B. Holbrook of Columbia University.

Stores force-feed aesthetically dubious, manipulative music to customers, they say. Even worse, background music cultivates bad taste, intrudes on consumers' freedoms and sense of privacy, and is symbolic of a "triumph of commercial greed over artistic creativity."

The dumbed-down music retailers typically play during the holidays becomes a form of "social control," Bradshaw says in a phone interview. "Musicians don't think of their music helping to sell toasters,"he says. "Music gets debased, and negatively affects the dignity of music."

Then there's this: "If you play the same music over and over again, it will drive your clerks insane," Bradshaw adds.

(Contact David Burger at dburger@sltrib.com.)