Rap records, like most manifestations of teen culture, are often intentionally obnoxious. The best are not merely loud but triumphantly so, boasting vocals that are equal parts poetry and provocation and backed by a beat that begs to be blared. On one level, that sonic assault is simply a function of teen territoriality, the desire to fence off a little part of the world, whether bedroom or street corner, with a wall of sound.

Mostly, though, the music's obstreperousness is essentially a celebration of itself, a stylized aggression that is its own reward. After all, for the rap artist, a gesture is everything -- it's worth remembering that in rap parlance, rhymes are not made but "busted." For all that, though, the violence is entirely verbal, for despite the occasional description of deejay decimation, the tough talk is less concerned with destruction than with construction -- specifically, building up the stature of the rapper.

No wonder, then, that rap lyrics tend toward an odd blend of street braggadocio and old-fashioned morality. Take "It's Tricky," from Run-D.M.C.'s recently released third album, "Raising Hell" (Profile PRO-1217). Basically a rap about the wages of stardom, it finds poor Run and D.M.C. complaining about how they're forever besieged by their fans. Female fans, especially. "They even bother my poor father, 'cause he's down with me," laments D.M.C.

Being true troupers, they cope with the situation, satisfying their fans' lust for rhymes and other favors. But in the middle of this fantasy of stardom run wild, the two take care to add, "They offer coke and lotsa dope/ But we just leave it alone."

Unlike most antidrug songs, "It's Tricky" isn't a warning that drugs are dangerous, but it boasts that Run-D.M.C. are above such bad habits. In other words, chumps do dope, not these two. Similarly, "Dumb Girl" doesn't argue against promiscuity as such, but observes what happens to teen-age girls who try to use sex to slip into the fast lane, concluding that anyone expecting a free ride to good times isn't worth pitying.

If that seems somewhat harsh, keep in mind that rap culture doesn't exactly put a premium on sensitivity. But Run (Joe Simmons) and D.M.C. (Darryl McDaniels) are not just big-mouth boors. True, "My Adidas" reduces personal pride to name-brand consumerism, but "Proud to Be Black" more than evens the score with the strongest musical affirmation of black power since James Brown's "Say It Loud -- I'm Black and I'm Proud."

Still, Run-D.M.C. stake their strongest claim on a musical level, having made the most of the link between rap and heavy metal. Last year's "King of Rock" may have clarified the connection, but "Raising Hell" really drives it home from producer Rick Rubin's AC/DC invocation on the title track to the surprisingly straightforward cover of Aerosmith's "Walk This Way." Even the album's minor points skew toward hard rock, from the use of "My Sharona" in "It's Tricky" to the live drumming in "Perfection."

Whodini, on the other hand, has moved in exactly the opposite direction on its new album, "Back in Black" (Arista/Jive JL8-8407). Whereas the group's second album, "Escape," became the bestselling rap record of all time by making the most of producer Larry Smith's grooves, his third album relies all too much on the wit and wisdom of rapper Jalil Hutchins.

It isn't that Hutchins is particularly lacking in wisdom. "Friends," from the "Escape" album, offered one of the best, common-sense arguments against promiscuity to turn up on a rap record; on the new album, both "One Love" and "Growing Up" advocate a strong course of moral and emotional responsibility.

But Hutchins' expression of these ideas is anything but witty. "One Love," for example, lards its logic with such hoary cliche's as "a bird in the hand is worth two in the bush," while "Growing Up" is littered with inanities like "you win some, and then you lose some." Sage advice it's not.

Even more disappointing is the inconsistency between pro-fidelity rap like "One Love" and the mindless promiscuity promoted by "I'm a Ho." Even the rhythm arrangements fail to redeem this effort; aside from "Last Night" and "Funky Beat," they're utterly pedestrian.

Still, at least the members of Whodini haven't resigned themselves to being cartoons the way the three Fat Boys have. As depicted on "Big and Beautiful" (Sutra SUS 1017), their third and latest album, the Fat Boys are wide-load lady killers, sexual gourmands whose way with women is topped only by their fondness for food. Of course the image is offered mostly tongue in cheek -- the title tune compares thin men to the Fat Boys with the line, "Why settle for a snack when you can have a whole meal?" -- which is good for a few chuckles even if it does turn their version of "Sex Machine" into an unwitting joke.

The rest of the gags are decidedly lightweight, but one track, "Double-O Fat Boys," a spoof on the James Bond spy thrillers, shows the trio to be superb comics. The number closes with a cliffhanger ending and promises a sequel.

Here's hoping that next time around the group will not only pick up where they left off, but expand on the idea.