Over the past several years, American and European popular musical tastes, as traced in sales charts, at least, have meandered off in somewhat different directions. On this side, heavy metal and its glitter-rock/teeny-bopper descendants have kept their hold over the younger listeners, California-rock and country-rock have made inroads into the great middle road, and disco has replaced R&B as the dominant BOR (black-oriented rock) idiom.

Across the watery divide, rock is in one way or another more simplistic, either bared in its New Wave minimalism or sweet-popped into Cheap Trick predictability. Disco has had a longer history and has developed a special dialect of its own called Europop - a lush, over-produced, multiharmonic style that suggests a symphonic grandeur behind the formula lyrics.

So far, Europop has made only a slight impact on U.S. buying habits, but its influence is spreading (the Bee Gees' last album, "Spirits Having Flown," had more than a touch of Europop in the production). Its greatest advocates have been ABBA, the Swedish corporate quartet that claims to have sold more millions of albums than anyone else in the world, and passed Volvo as Sweden's biggest-earning conglomerate.

Exposed to the U.S. airwaves via a series of single hits, ABBA has been intriguingly unpredictable. While some of the songs were remarkable only for their heavy harmonies, like "Dancing Queen," a couple displayed real emotion, a brittle resignation or bewilderment, like "The Name of the Game" and their best, "Knowing Me, Knowing You." Since their albums have only gradually taken root here, it's been easy to overlook the fact that songwriters Benny Andersson and Bjorn Ulvaeus had also written songs from the viewpoint of, for example, a teenage schoolgirl with a crush on her teacher.

"Voulez-Vous" has been released here with full pomp and behind the single release of "Does Your Mother Know." That song seemed to promise an album with some intelligent characterization, since the male narrator not only shows awareness of the too-young girl's intentions toward him, he's half-inclined to take her up on her proposition. And "Voulez-Vous," while offering little in the melodic or lyrical lines, treats the disco scene as the one-night meat market it is.

Alas, the formula has this album well in hand, and all the harmonics and regular changes of tempo and orchestrations cannot make it more than mildly interesting. One music-industry representative (from a different label) uses it in his office as Muzak, and for that, it's a good choice.

Then there's the new Paul McCartney album, "Back to the Egg," absolutely dripping with symbolism about McCartney's return to basic rock'n'roll and precious short on substance. While the old inside/outside Apple labels pasted on the Beatle's albums were effective and smart, the sunnyside-up and over-easy labels here are about as cutesy as a mortarboard hat in a sixth-grade graduation.

McCartney has no discipline; although he promises it often enough, he never delivers. He came up with just enough integrity to keep the disco-ish "Goodnight Tonight" single off this album, but he could not resist playing games with over-dramatic spoken tracks and nonsense lyrics.

After the Beatles began to have public internecine arguments, the other three all testified that McCartney had been the most pop-oriented of the four; Lennon wrote a rather scathing song denouncing McCartney's post-Beatles writing as mush. McCartney is certainly pop-oriented, but his evident self-satisfaction brings him terribly close to self-parody. It's all the more frustrating because hidden here and there on "Back to the Egg" are songs of at least temporary interest.

For the instrumental "Rockestra Theme," McCartney assembled a rock orchestra of two dozen musicians, including Pete Townshend, David Gilmour, John Paul Jones, Kennedy Jones and John Bonham. But what McCartney composes for this awesome ensemble is a repetitive chorus of first-lesson chords. If this is, as he has said, McCartney's idea of what a symphony of rock musicians could do, then it's time to bring back the one-man street-corner band.

"Back to the Egg" may not be as redundant as "Voulez-Vous" but, frankly, it's more tedious. McCartney could make a great living producing fancy jingles for soft drinks.

The second Dire Straits album, "Communique," is a half-success, and by comparison a great discovery. Mark Knopfler sounds more like the young Bob Dylan all the time (a fact Dylan has put to use on the album he's working on now).

Side one is an ambitious, lengthy, apparently endless paean to the American Old West, similar in type and tone to Dylan's "Knocking on Heaven's Door." It begins with a 5:22 track called "Once Upon a Time in the West," and flows almost inadvertently over the next two songs. If your attention wanders, you may miss the jump from one song to the next (if you liked the amiable repetition on the first "Dire Straits," you'll love this). The fourth and last song on that side is the title track, a mildly amusing socio-political polemic against secrecy.

Side two is far better, leading off with the (again) early-Dylanish "Lady Writer": "The way her hair fell down on her face / I recalled my fall from grace / Another time, another place." Perhaps the best track is "Angel of Mercy," which gently spoofs the angelic moonings of the '50s: "Angel of mercy, angel delight / Give me my reward in heaven tonight."

But it's still a trifle too bare, too laid back. It's hard to feel what Knopfler is (presumably) feeling in his songs. John Stewart says that Dire Straits and the forthcoming Fleetwood Mac album are the shape of rock'n'roll to come; if that's true, then there better be enough energy on the Mac album to go around. CAPTION: Picture, ABBA: A SLIDE FROM THE UNPREDICTABLE INTO FORMULA.