Renee Fleming will sing the national anthem at the Super Bowl on Feb. 2. (Andrew Eccles/Decca)

Renée Fleming has hit some important pop-culture markers in the past few months. In September, she went on David Letterman’s show to sing the Top Ten list. Now, she’s going to sing the national anthem at the Super Bowl. Musical attention at the Super Bowl usually focuses on the halftime show, but since this kind of attention is so rare in classical music these days, and since Fleming is the first opera singer ever to be accorded this, well, honor, the announcement has caused quite a stir.

Any time a classical artist appears in a nontraditional venue, some purist is probably going to make noises about commercialism and selling out. It’s hard to remember now the furor that Luciano Pavarotti caused when he made his first American Express ad, back in the ’70s. Times have changed, not least in that there are precious few classical artists today who could risk asking “Do you know me?” on national television, though Yo-Yo Ma, Josh Bell and Fleming herself could probably get away with it.

The outrage about this kind of thing has abated, and a good thing, too, because classical artists have been making what they could out of their renown from the dawn of the field’s history. Nonetheless, there remains a sense of disapproval in die-hard classical circles when one of their own steps out of the fold — when Fleming, for instance, makes an indie-pop album. There is a touch of sour grapes about such reactions; the field is on some level so hungry for recognition that many of the artists who make pronouncements about not wanting to sell out would almost certainly leap at the chance to appear on Letterman. And if Fleming is able to do it in a way that makes Letterman and his viewers want to know more about her, this is a good thing for classical music — not least because Fleming, for all of her explorations of different vocal avenues over the years, is in no danger of going over to the crossover/arena concert camp.

It’s certainly not a new thing for classical musicians to perform the national anthem at sports events. Robert Merrill, the 20th-century American baritone, became practically synonymous with the New York Yankees, singing on Opening Day, the Fourth of July and other occasions. Dozens of singers and even instrumentalists have taken the anthem challenge, from Placido Domingo to NSO violinist Glenn Donnellan, who performed the anthem before a Nats game on a violin made from a baseball bat.

The question is whether what Fleming performs at the Super Bowl will actually be an exemplar of so-called “classical music.” Fleming is conversant in a number of vocal styles — you may or may not like her indie-rock album “Dark Hope,” but you can’t argue that she took several steps away from her operatic sound when she recorded it. When she tries out so-called popular vocalism, she tends to put on a breathy, faux-emotive affect that has bled over even into some of her classical performances, and that can drive some people crazy. Whatever she does will certainly come under the scrutiny of the Fleming-watchers on, an opera-savvy and bitingly satirical Web site where criticism can often veer below the belt (in several senses of that term).

Most of America, however, will just be looking at a pretty woman singing the anthem in a pretty voice, with high notes to burn. The appearance is sure to give yet another boost to Fleming’s growing superstar status outside the classical world. And if she needs a cheat-sheet for the words, as she did for Wagner’s “Traeume” at the Marilyn Horne gala at Carnegie Hall last week, you can be sure it will be kept off camera.