"Viva Italia!" has its dreadful as well as its delightful moments, but this bawdy nine-episode omnibus comedy - a sort of "Boccaccio '78" opening today at the Dupont Circle - ends an uneven 90 minutes on a note of such boisterous innocent merriment that to see it is to risk being overjoyed.

Alberto Sordi, who stars in three of the sequences, and is the film's clowning glory, appears in the finale as the straight-man survivor of a late great comic, and he leads mourners at graveside in eulogizing the zany stiff at their feet. The eulogy turns into a litany of grievances against the hog who hoarded all the laughs for himself, however, until the straight man tries telling a few of the bad old jokes alone.

The crowd's tears turn to titters and then hysterics, and soon the liberated straight man is leading the ensemble in a song and dance around the grave, with two workmen providing a tarpaulin that serves as a curtain - all the world may be a stage, but some have to wait longer than others for the spotlight to find them. This sequence is at once patently contrived and shamelessly affirmative.

The film is at its best when it celebrates attitudes, values and fallibilities either utterly Italian or vaguely Italian, and at its worst when it takes a stab at social or political commentary. Vignettes about kidnapping and political terrorism, for instance, have an unsettling ring in light of the recent activities of the Red Brigade, and they are intellectually primitive besides.

A moralistic scowl at the employment of youths in pornographc films turns out to be at least as distasteful as the trend it deplores. And Vittorio Gassman's turn as a traditionalist priest who shocks an improverished parish out of its angst with a recital of platitudinous placebos is overly obvious even in the context of a deliberately obvious film.

There are other scenes, however, that work splendidly. Originally there were 11 episodes altogether, but the American distributor trimmed out two of them as being "too Italian" for audiences here. "Too" Italian? The nine remaining could never be mistaken for Swedish dirges or German sulks.

Three directos - Mario Monicelli, Dino Risi and Ettore Scola - and three writers - Age-Scarpelli, Ruggero Maccari and Bernardino Zapponi - contributed to the film, and since it is never pointed out who did what, all can share in the victories as well as the intermittent failures.

The film's first episode opens with a promising jerk. A sweetly mediocre chanteuse named Fiorella (Orietta Merti) is being propelled on a moveable stage into the audience at a barish nightclub; it stops abruptly but she keeps singing. In the back of the room her husband (Ugo Tognazzi) not only tries to lead cheers for her lackluster performance, he goads the other men into lewd fantasies about her. "Fiorella, you are Beethoven's Eroica!" he shouts at one point, and, at the next, "Fiorella, you are a sex bomb!"

This is a man determined that the world join him in worship of his heart's desire and his life's work, and he goes to great lengths to keep her in the cockles of the public's heart.

Later Tognazzi plays the deranged cook at a mad inn where the hideously dressed bourgeoisie wait with quivering palates for a meal whose ingredients, including an octopus, are being used as ammunition in a furious kitchen war. Later the unknowing clientele blithely coo over a stew in which a cigar butt has swum and a shoe sunk. The message is broad but then so is the medium; at times the prevailing philosophy of "Viva Italia!" is that nuances are things that only get in the way.

On the other hand, Sordi returns in an episode that is essentially an extended nuance. A middle-aged husband is trying to trick his elderly mother into thinking a home for the aged is really a luxury resort for the posh. The sequence lacks concluding punctuation, but it takes on added poignance if we recall that 20 years ago Sordi played the overgrown mama's boy in the Fellini film that is least debatably a masterpiece, "I Vitelloni."

Sordi's triumph and the film's finest sequence find him behind the wheel of a white Rolls-Royce, playing a kind of jet-set ecclesiastical aristocrat who happens upon the victim of a mugging while driving to a party. The poor bleeding man is reluctantly pulled into the car and hauled by the driver from hospital to hospital, only to be turned away on account of bureaucratic technicalities at each one.

The comic focus of this sequence is not on Italian medical care, however, but on Sordi's fabulous jabbering fop, a man whose magnificence derives from his being utterly obivious to things that matter in the world. He had just left a club called "Jackie O's," and he subjects his nearly unconscious passenger to a stream-of-conscious monologue that meanders or leaps from slapdash religious and political philosophy to furtive chapters from his fanciful erotic memoirs.

The soliloquy is a marvel, but Sordi interprets the character in ingenious physical ways as well. He has managed to articulate ravenous self-obsession through a way of walking, so that each time he gets out of the car and insinuates himself toward a hospital door he becomes funnier than the time before. Too much of the film may depend on the splendor of such performances, and the screenplay does appear to have been rather hastily dashed off, but if it can inspire a burlesque as sublime as Sordi's, more power to it, and viva "Viva Italia!"