New York City Fresh Festival shows will be held at 2:30 and 9:30 p.m. Saturday at the Washington Coliseum, Third and M streets NE. An incorrect date and place appeared in yesterday's editions.

If a single word could epitomize the hip-hop movement, it would be "fresh." To be fresh, in the hip-hop lexicon, is to be new and exciting, to take a different tack on things. Understandably, it has become the hip-hop culture's highest compliment.

Still, it's a far more difficult task to define "fresh" in musical terms. For instance, Run-D.M.C., Kurtis Blow, the Fat Boys, Whodini and Newcleus are currently touring the country as the New York City Fresh Festival (they arrive at the D.C. Armory Sunday). Judging from each act's latest album, the promoters certainly have the lineup pegged as far as quality goes. But what of the music?

There's no formula to the fresh sound; that would almost be a contradiction in terms. Instead, what keeps the best of these performers fresh is their ability to find innovative ways of being themselves, thereby maintaining both novelty and a consistent identity. That's no easy task -- especially given the speed with which fashions change in the hip-hop world -- yet it's one that Run-D.M.C. take to with remarkable aplomb.

On the surface, the nine selections on "Run-D.M.C" (Profile PRO-1202) are a decidedly varied lot. "It's Like That," the duo's first hit, employed a stark combination of synthesizer and percussion to underscore the gloomy urgency of the hard-times message; "Rock Box," by contrast, beefs up the party-time boast with nasty, screaming guitar; while "Jay's Game" recaps bits of "Jam-Master Jay," the twosome's tribute to their mixer.

As rappers, DJ Run and D.M.C. are thoughtful and provocative, supporting their often acerbic observations with an aggressive delivery. But what most stands out about "Run-D.M.C." is its hard-hitting sound. Run-D.M.C. have almost invented the rap equivalent of heavy metal, where sonic impact comes first, the beat and the message second. Nowhere is this clearer than on "Sucker M.C.'s" -- a workout built around an overwhelming drum mix.

The man responsible for that drum mix is Kurtis Blow, but it's worth noting that he hasn't attempted to bite their style, even though Run-D.M.C. are featured on the opening cut of his new album, "Ego Trip" (Mercury 822 420). The reason is simple; Blow has tricks enough already. "8 Million Stories," recorded with Run-D.M.C., uses a fairly dense instrumental arrangement on the chorus to offset the lean lines of the rap, giving the piece a striking sense of grandeur. Blow also knows how to mix plain talk with his rhymes, so that his records carry an extra bit of street feel, but his most impressive moments come when he exploits the studio, as he does on the intoxicatingly sinuous "AJ Scratch."

Blow extended his arranging skills to "Jailhouse Rap," the high point of "Fat Boys" (Sutra SUS 1015). Tracing the Fat Boys' mythical life of crime, brought on not by hunger but by gluttony, "Jailhouse Rap" manages the unique trick of pulling a serious message out of a joke, and the instrumental break is central to the transition. But though the rest of "Fat Boys" carries a similar good humor, the album tends to bog down in such tiresome effects as the "Human Beat Box."

It also helps for a rap group to have something to say, and on that count, the Fat Boys are real lightweights. Not so Whodini, as the duo shows on its second album, "Escape" (Arista/Jive JL6-8251). Although this pair can shake a lot of booty while saying almost nothing at all -- "Five Minutes of Funk" is just that, even though there is about as much content in the title as in the raps -- they also know when and how to put their point across. "Friends," for example, is perhaps the most poignant polemic against casual sex to hit the airwaves in years.

Whodini's bottom line is still the music, though, and the duo's rapid-fire delivery, which seems to double up the beat of their backing tracks, is a central part of their charm. But so are the instrumentals, especially "Out of Control," a studio-savvy bit of electrofunk that recycles bits of "The Haunted House of Rock" to great effect. As most of "Escape" clearly shows, Whodini understands the electronic end of hip-hop better than most rap acts.

But not as well as Newcleus, which is only fair because, as is demonstrated on "Jam on Revenge" (Sunnyview SUN 4901), rap plays only a minor role in the group's sound. Most of these tunes are instrumentals and owe far more to the likes of Man Parrish than any of the Bronx rappers. In fact, when the group does indulge in vocals, they tend to become gimmicks, as on the Clara Peller-inspired "Where's the Beat?" or the Munchkin-voiced title track. Unfortunately, such stunts go stale in a hurry, which is no blessing to any act hoping to remain fresh.