As it turned out, I couldn’t quite manage The Voice–the hosting gig went to someone else–but I quickly realized that if I wanted anything to do with NPR, I’d need to figure it out pretty quick. NPR’s ascendancy has been striking–“Morning Edition” and “All Things Considered,” its drivetime shows, are the second and third most popular radio programs in the country, and the network’s listenership continues to grow–up 18.5 percent in 2001 alone. A big part of the reason is the unparalleled quality of its news coverage. NPR’s journalism is in-depth, accurate, fair, intelligent, and, not insignificantly, virtually commercial-free. In the sea of vituperative right-wing radio, NPR is an island of sanity, civility, and seriousness. And its reporters and personalities are truly talented: Their ability to explain complex issues in plain, sharp, value-neutral language may be unsurpassed in all of broadcasting.

But the network has also become something of a victim of its success. If you listen to a lot of NPR, you realize how similar it all sounds: no matter who is talking, or what they’re talking about. There’s a simple reason for the homogeneity: The drivetime shows, the 800-pound gorillas of public radio, have become so successful that the sensibilities of their influential hosts and correspondents have come to dominate all other NPR programming. Susan Stamberg, Nina Totenberg, Bob Edwards, Carl Kasell, and their peers have a tight grip on the sound of NPR, especially Linda Wertheimer, whose cadence–a sort of patrician delay–still defines the NPR sound even though she no longer serves as a host. It is a sound created by boomers for an audience of their contemporaries. The Voice is theirs, and if you can’t pull it off, as I quickly discovered, you’d better get out of the way.

It is an extremely appealing Voice–to a certain demographic. About 20 million people tune into NPR each week. Their mean income is $78,216, and their average age hovers just below 50. Nearly 90 percent of those who shared their racial information are “non-Black/non-Hispanic,” according to NPR survey data. In other words, the people whose Zeitgeist Edwards et al., have been extraordinarily effective in catching are affluent, middle-aged white liberals, who tune in to the drivetime shows on their way to work and sometimes continue listening for the rest of the day. This demographic just adores NPR, and NPR gives the love right back. You like Stamberg? We’ll give ya Stamberg: She was a guest on the recent “Morning Edition” radio play I’d Rather Eat Pants–“a comic tale of an elderly couple’s cross-country trek on a young slacker’s motorcycle.” You like Kasell? He’ll bring his dry humor to “Wait Wait … Don’t Tell Me!,” a quiz show during which a wacky gang of aging journalists crack wise about the week’s news. Winners even get to have Kasell’s voice on their home answering machines.

And it’s not just a matter of spreading the Zeitgeist personalities around. NPR also pressures new talent to mimic the style that those personalities have established. In an interview with the Philadelphia City Paper, Tavis Smiley, the former host of Black Entertainment Television’s “BET Tonight” and new host of “The Tavis Smiley Show,” pointed out that at NPR, “I have to be authentically black, but not too black.” And his show bears that out: It’s a good program about black topics that follows the same respectful, all-sides-of-the-issue formula of all the other good, respected programs that came before it. On the same day last month, for instance, “All Things Considered” and “Tavis” both ran stories on education reform, hitting many of the same points. NPR’s strategy for holding onto its “A.T.C.” and “Morning Edition” listeners is to develop programs that are slight variations on the originals. “Tavis” is the ethnic “A.T.C.”; “Talk Of The Nation” is “Morning Edition” with phone calls. NPR’s idea of cultural diversity is to recruit black personalities, like Smiley and new “A.T.C.” host Michele Norris, and ask them to assimilate to the liberal, white, boomer mentality that dominates NPR’s “All Things Considered.”

This may make for a successful system of branding, but it also drives many of those who don’t fit the demographic crazy. One can only hear so many stories about aging Broadway producers and bilingual poets before they all start to blur together in a boomer-friendly fog. The types of programming that appeal to, say, young people, have gone all but ignored in recent years. Daniel Pinkwater fondly reminiscing about the time his mom took him to try to see the Lone Ranger may resonate with his middle-aged contemporaries, but if you don’t share those experiences, it just sounds self-indulgent and corny. It’s not that hip cultural programming is impossible on public radio–Public Radio International (PRI) shows like “Studio 360” and “This American Life” do it all the time. It’s just something that the polite folks in the NPR building at 7th and Massachusetts Avenue in D.C. have a very hard time pulling it off.

Not that they haven’t tried. A few years ago, NPR launched a show called “Anthem,” a contemporary music program “based on the coffeehouse model.” Few of NPR’s member stations picked it up, however, and it was discontinued after a short run. The contemporary music programming NPR does run on shows like “All Things Considered” tends to focus on singer-songwriters and Ghanaian guitarists, the kind of artists that educated older listeners enjoy, or want to say they know about. Even the commercial rock groups NPR occasionally profiles tend to be older people’s ideas of what younger people ought to like, bands like the Wallflowers. And all the cultural programming is so mind-numbingly appreciative–a parade of reviews and portraits, of writers and books, films and filmmakers, photographers and their retrospectives–all so uniformly upbeat and positive that the listener hungers for just one discerningly negative comment.

On occasion, an inspired idea makes it through the programming meetings–such as the decision to commission commentaries by the darkly funny poet Andrei Codrescu. NPR’s “Car Talk” is also genuinely amusing–though, tellingly, never more so than when the working-class Boston hosts, Tom and Ray Magliozzi, tweak their grave NPR colleagues. Mostly, though, when NPR tries to be funny, the result is a cringe-inducing show like “Wait Wait … Don’t Tell Me!,” an excuse for a group of panelists with a suspicious similarity to their target audience to express their delight and whimsy at how clever and informed they are. Most of us don’t look to Beltway insiders for jokes, just as we don’t really want the local weatherman to yuk it up with the sports guy–it’s cutesy and forced, only funny if you are an NPR junkie or a weatherman yourself.

The less formulaic stuff on public radio usually comes from another source: PRI, NPR’s younger, smaller, more risk-taking rival. Though you might not be aware of it, only about a quarter of what you are likely to hear on any local public radio station is produced by NPR. Another fifth–including shows like “Marketplace” and “A Prairie Home Companion”–comes from Minneapolis-based PRI (the rest comes from the local station itself). Both NPR and PRI get a small amount of their operating revenues–less than 2 percent–from the federal government. The rest comes from foundations and corporate grants and, most importantly, from fees they charge the local stations for their programs. Not surprisingly, the two networks compete vigorously to sell to the affiliates.

Unlike NPR, PRI is blessedly free of The Voice. Its programs don’t seem quite as reflexively aware of what they are supposed to sound like. The difference between PRI and NPR is kind of like the difference between a bull session with particularly astute friends and a lecture by a knowledgeable but vaguely condescending college professor. Kurt Andersen, host of “Studio 360,” can spend an hour talking about the history of superheroes with a novelist you’ve never heard of without, for the most part, being irritating. Christopher O’Riley of “From The Top,” PRI’s engaging showcase for young musicians, counts among his influences Howard Stern. Many PRI shows are more effective in attracting younger audiences than their NPR counterparts. This is partly due to the fact that the main NPR shows are news-driven, and younger people–as is well known–tend not to follow the news. But a more apples-to-apples comparison makes the point. PRI’s drive-time business program “Marketplace” is just as newsy as NPR’s “Morning Edition” and “All Things Considered,” though with a looser, sharper feel. But 41 percent of those who tune into “Marketplace” are under 44; “M.E.” and “A.T.C.” pick up just 34 percent of listeners from that age group. “Marketplace” also has a greater percentage of listeners who are older; listeners of the NPR news shows are far more concentrated around the boomer mean.

There are a number of reasons for PRI putting out shows that are attractive to both older and younger listeners. PRI carries very little infrastructure–it distributes or co-produces all of its shows, and pumps much of its news in from the BBC–and subsequently doesn’t have to spend much to maintain its programming. This allows PRI to spend its discretionary money on riskier but more rewarding projects. NPR’s endowment is maintained in large part to protect NPR news against periods of recession, when underwriting revenues dry up; PRI’s program fund is designed to seek out innovative shows and “engage broader audiences.” And NPR is, in part, hemmed in by its corporate structure. Station representatives, who generally give priority to their station’s interest, occupy 10 of the 17 spots on NPR’s board, and they are unlikely to push for original programming that may not fit with their station’s identity. PRI’s board is completely independent.

In theory, it ought to be possible to produce programming that appeals to both aging boomers and twentysomethings–Ed Sullivan, after all, featured both The Beatles and Doris Day. In reality it’s very hard to do. Robert Goldfarb of ArtsMedia LLC, an independent music and radio consulting company, explains NPR’s dilemma. Its producers aren’t going to attract significant numbers of young listeners to its staid flagship just by including the occasional disparate element–a biting commentary, say, or a punk song. But if they include enough such programming to attract a sizable portion of that demographic, they risk scaring off their current listeners. That means, argues Goldfarb, that NPR is fated to ride the current wave as long as it can before dumping the boomers and scrambling for the next generation of listeners.

That’s not an altogether terrible thing. The current division of labor between NPR’s reliable news and PRI’s edgier culture programming arguably gives public radio listeners the best of both worlds. And while it’s frightening to imagine what NPR will sound like a decade from now–lots of stories about colonoscopies and Rod Stewart still going strong at 65–it’s possible the network will find a way to change, albeit fitfully, with the times. NPR today, after all, is sharper than it was 15 years ago, more soccer mom than radical chic; there are fewer pieces on Guatemalan macrame co-ops and more on the latest in Internet filters. Today’s NPR braintrust has not quite figured out how to satisfy everyone, but at least it’s making its aging constituents happy. Perhaps in its next iteration NPR will find a way to bridge the generation gap–that divide between boomers and the rest of us.