IN 19 YEARS, BOSTON'S ALBUMS HAVE BEEN WORTH WAITING FOUR.(ENTERTAINMENT)

Byline: GARY GRAFF Knight-Ridder

``Let's face it; there are always changes in rock 'n' roll since the last Boston album,'' Tom Scholz says. ``I mean, there's been a new president for every album.''

Scholz isn't kidding. In 19 years, his band has put out just four albums; Ford, Carter, Reagan and Clinton are the White House touchstones for each release. Madonna has put out more than twice as many albums in half that time.

Climates musical and political may have changed, but Boston hasn't. The sound on ``Walk On,'' which came out last June and is Boston's first album in seven years, is of a stylistic piece with the album's three predecessors. The production is dynamic and Teflon-clean. The guitar assault comes courtesy of Led Zeppelin, the melodic sensibility from the Beatles.

And there's a stadium-size drama and bombast drawn from the music Scholz learned as a child.

In other words, the world of alternative and modern rock has made no impact whatsoever in the self-constructed home studio where Scholz crafts Boston hits such as ``More Than a Feeling,'' ``Long Time'' and ``Don't Look Back.''

``I don't buy CDs,'' the 48-year-old multi-instrumentalist, songwriter, producer and engineer says in his flat Bah-ston accent. ``I do hear other kinds of music when I'm out shooting pool or playing hoops, at the health club or just going out partying. The thing is, I like it all, with the exception of rap, which I hate.

``But that doesn't matter. Whatever I like, when I sit down to work on songs, they always end up sounding like Boston songs. I can't help it. I can't write anything else.''

On the plus side, Boston enjoys the kind of readily recognized signature sound most bands would kill for. The negative is criticism that Scholz and company are spinning their creative wheels, neither progressing nor keeping pace with the times.

The fact of the matter is it works. Boston has sold more than 20 million albums since 1976. At 11.5 million copies, its first album a sonic prototype for bands such as Journey, Styx and Bon Jovi is the top-selling debut of all time. Even ``Walk On,'' hampered by a lack of promotion from the record company and a music scene that's pointedly indifferent to what Boston has to offer, has sold more than a million copies.

In research conducted by Sony Music whose subsidiary, Epic Records, released the first two Boston albums the group shows up as one of the most widely recognized acts in every age group from 10 to 52.

``We have a pretty wide appeal, anywhere from high school kids to people our own age,'' says Brad Delp, who sang on the first three Boston albums and is along on the group's current tour. ``There's a lot of people who bought the first two records and are pleased there hasn't been any drastic change in the way the band sounds, and a lot of kids have latched on to it over the years, too.''

Scholz gets full credit for that consistency and durability particularly in light of Boston's erratic release schedule, which hardly fosters any kind of career momentum. Born in Toledo, Scholz moved to Boston to study engineering at the Massachusetts Institute of Technology. He started making music in 1971 as a free-time endeavor; his day job was at Polaroid, where he helped invent the company's instant film system.

Music was more than a hobby, though. ``I think I was a working at Polaroid trying to earn money to record,'' Scholz says. He approached it with the exacting, meticulous ways of an engineer, taking total control in crafting his songs and not letting them out until he was absolutely satisfied.

His results won fans, but Scholz's methods rankled record company executives and Boston bandmates; during the mid-'80s, he was in court with both entities over allegations of breach of contract, which he defeated, and underpayment, which he settled out of court.

Scholz also succeeded in the musical equipment world. His Scholz Research & Design, Inc., turned the Rockman a Walkman-sized device that allows musicians to re-create the Boston guitar sounds into one of the most popular accessories for musicians.

These days, however, Scholz is more interested in creativity than technology. He sold SR&D last year, though he still enjoys playing the mad inventor; he built the world's largest Hammond organ for the current Boston tour, and prodded by a litany of mostly basketball-related injuries he's developing some orthopedic aids.

Scholz also re-tooled his studio to make it more user-friendly. ``I can go in and punch a few buttons, and be a creative musician rather than having to think like an engineer and producer all the time . . . all of that stupid stuff that gets in the way of the original idea of the song,'' he says. That allowed him to make ``Walk On'' in just three years a sprint by Scholz's standard.

Which begs one last question will Scholz be faster in making the next Boston album?

``I have a hard time getting that down to under five years,'' he says with a laugh. ``With everything now in place, I'm actually looking forward to working on the next one. I'm predicting it in three (years), but I don't want to commit to that.

``I can guarantee you I'll be heartbroken if it's not out before the millennium. It's got to be out before 2000.''