Because of technological advances, copyright is a constantly evolving field, and right now there's an intriguing question as to whether digital sampling technology -- which records a sound digitally and then plays it back at any pitch over the range of an entire keyboard -- is protected by current copyright law.

The technology allows musicians, producers and equipment manufacturers to appropriate (some would say steal) well-known artists' signature (but not trademark) instrumental and vocal sounds directly off recordings. The sampled sounds -- which can range from a particular drum sound to a guitar riff -- are then incorporated in new recordings.

Sampling is a relatively recent development, with samplers ranging from top-of-the-line models like Synclavier Digital Music System (which can run from $140,000 to $300,000) to the bottom-of-the-line Casio SK-1 (less than $100 in some stores).

But, many are wondering, does copyright, which protects the sequence of notes in a composition, protect the individual notes? The use of sampled sounds is becoming increasingly common, and the copyright question has become public because of a review under way at the New York local of the American Federation of Musicians involving a sampled drum sounds used by Jan Hammer in his "Miami Vice" theme. Conga player David Earl Johnson says he traded "favors" with Hammer in the studio before the show went on the air and that Hammer "sampled" his congas, which are, of course, quite pronounced in the theme music. Johnson says he is waiting for a ruling from the union, but admits he may have to sue.

"I'd like to get paid," he told Billboard. "If your work is used, you should get paid. He's got me and my sounds for life and there's no compensation."

From now on, Billboard suggests, musicians may have to identify whether they're working at a recording session or a sampling session. folo10f Pulling a Parody An antiapartheid radio parody of the well-known jingle "There's more for your life at Sears" was pulled off the air and all copies destroyed under an out-of-court settlement reached last Friday between the parody's distributor and the giant Chicago-based retailer.

American Comedy Network Inc., based in Bridgeport, Conn., has already destroyed or erased all copies in its possession, said creative director Bob James, who thought up the parody, "South African White Sale."

Sears, Roebuck & Co. had sued the company, charging violation of certain trademark rights, defamation and libel. Under the settlement terms, ACN, which distributes comedy skits to about 145 radio stations nationwide, wrote to its subscribers strongly urging them to destroy their copies, adding that they risk a lawsuit if they don't.

The skit that prompted the lawsuit included lines such as: "What's new at your local Fears Store? Whites control, blacks are mad, Johannesburg is awful sad, South Africans live in Fear. Tutu's hot, says boycott, worldwide sanctions hurt a lot, but still you can shop at Fears."

Sears' attorney Floyd Mandell said, "Sears is extremely pleased with the settlement and only regrets that litigation was necessary," and pointed out that its customers were confusing Sears as the target of the parody when, in fact, the company had a policy against doing business in South Africa because of apartheid. The Beatles' Musical Roots

Rhino Records, which did quite well with "Cover Me," a collection of songs written by Bruce Springsteen but performed by other artists (and in some cases only by other artists), has now come up with "Beatle Originals," a lively collection of the original versions of 13 songs that helped to make the Beatles famous before they started writing their own material. Included are three Larry Williams tunes ("Dizzy Miss Lizzy," "Bad Boy" and "Slow Down"), three Carl Perkins songs ("Everybody's Trying to Be My Baby," "Matchbox" and "Honey Don't"), as well as cuts from the Donays, the Shirelles, Arthur Alexander, Little Richard, Buddy Holly, Buck Owens and Dr. Feelgood and the Interns (not to be confused with Doctor and the Medics, who achieved an art transplant with their revival of Norman Greenbaum's one-hit '60s wonder, "Spirit in the Sky").

Some of the cuts on "Beatle Originals" are more obscure than Beatleologists might like, but Rhino notes that songs like the Isley Brothers' "Twist and Shout" and Barrett Strong's "Money" are readily available elsewhere. If nothing else, this album is a reminder of the varied musical roots that originally inspired those four Liverpudlians and of the colorblind -- and genre-blind -- attitude they brought with them. Odds and Ends

Wal-Mart, the giant retail chain that recently pulled 32 rock-oriented magazines off its shelves and that had previously withdrawn a number of rock and comedy albums from its racks, pulled David Lee Roth's new album, "Eat 'Em and Smile," but let the cassette remain on sale. The reason, according to Billboard: the scantily clad woman on the album's inner sleeve . . . Taylor Hackford, who has made some very successful films that have spawned No. 1 singles ("An Officer and a Gentleman," "Against All Odds," "White Nights") will be making his first real music film since "The Idolmaker" when he tackles "La Bamba," a biographical film on early rock singer Richie Valens. Already slated for key impersonations: Brian Setzer as the Big Bopper, Marshall Crenshaw as Buddy Holly, Howard Huntsberry of Klique as Jackie Wilson . . . Another music biz film in the works is "Ishtar," starring Warren Beatty and Dustin Hoffman as a pair of songwriter-musicians. Beatty and Hoffman are already in the studio cutting an album of songs written by Paul Williams, who will coproduce the project with Michael James Jackson.