AMERICA IS getting the "Hill Street Blues" blues.

We get old devil bluesies like these from commercial television networks. In their zeal to please everybody a little bit, the networks have neither the time nor the inclination to care about pleasing some people a great deal.

"Hill Street Blues" (the "blues" in the title are the boys in blue) is NBC's brilliant, funny, shocking, acerbic, bighearted and uncommonly rewarding serio-comic police series that has developed, since its premiere on a Saturday night in January, legions of devoted, even fanatical followers. But Nielsen doesn't count legions, only millions of homes, and there haven't been quite enough of those to satisfy the Gorgon and ensure the survival of the show.

Hence the blues: People who love the show go around saying things like, "Any TV program this good has to fail." Thirty years of controlled and cultivated network mediocrity lead viewers to such dire and melancholy conclusions. Generally, the more character and wit a TV series has, the more distinctive and flavorful its outlook on life (if it even bothers to have an outlook on life, or on anything), the feebler its chances for widespread mainstream acceptance.

But the creators of "Hill Street Blues" -- producer-writers Steven Bochco and Michael Kozoll -- are not despairing. The program's time slot -- Saturdays at 10 p.m. -- is one of the worst in TV, but from MTM Productions in Hollywood, Bochco and Kozoll say it isn't a hopeless situation. "Saturday nights traditionally don't lend themselves to cop shows," says Bochco, "but we're loath to be moved now. I don't think NBC has that much strength on that many nights anyway" so that another time slot might not make that much difference.

"Hill Street" began with the grimpy "Walking Tall" as a lead-in. That series stumbled and fell with a thud and now Fred Silverman's latest pet project, "Gangster Chronicles" (an anemic cross-breed between "The Untouchables" and "The Godfather" is offering "Blues" better 9 o'clock support.

By any sane standard, if sane standards are applicable in a world gone mad, "Hill Street Blues" is far, far and away the best new series of the season. It's all about a world gone mad, the urban landscape, but its attitude is not despairing or hysterical. In fact, in depicting life inside a perpetually beset big-city police precinct, the creators of the program succeed where the makers of the theatrical film "Fort Apache, the Bronx" failed.

"Hill Street" surveys the jungle with a wickedly but compassionately jaundiced eye; it has a tone more rarefied and realistic than the mushy-preachy "Lou Grant" (a program less socially conscious than socially self-conscious) and as a portrayal of men (and women) in groups, it outranks such ensembles as "M*A*S*H."

The question remains: Is there room on television for a program that is truly in a league by itself?

Recent ratings offer some hope. After a slow start and a so-so few weeks, "Hill Street" began to stir toward the break-even 30 percent audience share it needs to survive. CBS threw another of its rube-tube hayseeders, "Concrete Cowboys," at "Hill" and hurt it at first, but in the most recent ratings available, for Feb. 28, "Hill Street had a healthy 16.8 rating and 31 share. It ranked 42nd among the week's rated shows (up 20 places from the previous week), while "Cowboys" had fallen to a well-deserved 57th place.

That CBS sent "Cowboys" against "Hill Street" is consistent with a network maxim: Never try to buck a sophisticated show with a more sophisticated one; always go the other way. Industry sage Paul Klein once characterized a mainstay of the viewing audience as "kids and dummies." They're the constituency most network shows seem to use as a base; anything else is gravy. "Hill Street" aims higher but will need the kids and dummies too.

To lure them, there's the NBC promotion department which, when it bothers to advertise "Hill Street" at all, makes it sound like just another piece of slack-brained pap. "We're trying to appeal to a sophisticated audience as well as getting everybody else," says Kozoll. "We think there's something in the show for everybody, we're not shooting at the knees, and we want to do something we can be proud of."

However large or small the audience for the show, it is, to judge from mail and comments, an extremely devoted one. Sander Vanocur of ABC News waltzed up to NBC President Silverman at a pre-inaugural bash thrown by RCA here and implored him to fight for the preservation of "Hill Street." Silverman assured him, "We'll take good care of it," but his enthusiasm for the show is, to judge from NBC promotion, considerably less than his zeal for such Bonzoids as "Number 96" and "Lobo."

A seasoned NBC spokesman in Burbank, meanwhile, deplores on the face of it the notion that anything truly great in television is doomed to fail -- that "Hill Street" is literally too good to succeed.

"People automatically assume that," he scowls. "They don't realize that assumption is the mother of -- up." He says that in its early weeks, when "Hill Street" was juggled annoyingly between Thursday and Saturday nights, NBC was cleverly testing the waters and trying to induce "sampling" of the show by the audience.

"The affiliates love the show, and it's gotten as good a critical reaction as any one-hour drama I can recall," the spokesman says. "The network has bought more shows and it's going to stay on. How long, I don't know, but the executives love it."

Bochco and Kozoll -- who, when asked their ages, say "Together we're 77" -- don't think there's any such thing as "too good for television," even if the phrase has been used as a compliment for their work on "Hill Street."

Kozoll says, "Television is as good as you can be. I think it's dandy." Why, then, aren't there more shows on the air as good as theirs? "I think what we're doing different is -- we're better," says Bochco. "I know that sounds arrogant but what we have is a very workable concept. We're not doing 'neat' storytelling, everything tied up in a bow, a resolution every 48 minutes."

"The show really does partake of a kind of philosophy," says Kozoll. "Our best shows have had a kind of philosophical underpinning, almost a one-line theme. We're being funny but we're making a statement. It's not just an eclectic selection of little vignettes." m

It helps to have an extraordinary and diverse cast capable of realizing every nuance that's there in the script and of adding a few of their own. Each week they struggle in unison or in factions or utterly at oods against the hostile universe embodied in a few square blocks of an American city. They have learned that lunatics run the world, and they know that life's victories come mainly in terms of survival and in retreating to peace at the end of a long day's journey into right-back-where-you-started.

They're a great bunch of guys, and if anything happens to them, it will be a crime against television -- hardly the first, hardly the last, but it will hurt just the same. "I'm an eternal optimist," Bochco says gamely, but if life is rarely fair, network television almost never is. We should enjoy life and "Hill Street Blues" while we can.