David Bowie is the most interesting and exasperating pop music figure of the '70s. His often elusive but always provocative persona and music have cloaked him with an aura of independence and challenge that sets Bowie apart from most of pop's bland, commonplace practitioners.

That's why he-more than Iggy Pop-is the true godfather of the new wave/punk rock movement. Though Bowie's elitist, occasional art-rock instincts are contrary to the primitive, grass roots punk style, he shares the new wave emphasis on personality and viewpoint.

But his shifting, chameleonlike approach may be working against him. Bowie's rapid moves from rock to soul/disco to, techno-rock have struck even some of his loyalists as gimmicky and, therefore, not worth serious attention. The moves were, some have charged, more role playing than carefully conceived musical steps.

Apparently shaken by the disappointing commercial impact of his "Low" album early this year, Bowie has broken a lengthy press silence to affirm his commitment to the techno-rock/cum/art-rock exploration that he continues in his new "Heroes" LP (RCA AB 4139).

"The only reason I've decided to do these interviews is to prove my belief in the album," Bowie said in one of a series of meetings with the press in London. "Both 'Heroes' and 'Low' have met with confused reactions. That was to be expected...

"But I didn't promote 'Low' at all, and some people thought my heart wasn't in it. This time I wanted to put everything into pushing the new album. I believe in the last two albums ... more than anything I've done before.

"I mean, I look back on a lot of my earlier work and, although there's much that I appreciate about it, there's not a great deal that I actually like. I don't think they're very likable albums at all. There's a lot more heart and emotion in 'Low' and, especially, in the new album."

The result is at once a more conventional and less enticing work. For all the remoteness of the instrumentals on "Low," the release contained some of the most striking music Bowie had produced in years.

"Heroes" reunites much of the "Low" cast (notably synthesizer whiz Brian Eno) and setting (Berlin), but it is unlikely to restore Bowie's commercial momentum. Even with the barrage of interviews.

"Low"-recorded last year-was Bowie's most dramatic and effective musical move since "Ziggy Stardust," his '72 rock classic. In "Low," Bowie edged toward the cool, detached, German techno-rock sounds of Kraftwerk, a band he admires so much he played its albums over the sound system during intermissions on his last U.S. concert tour.

Rather than team with that band, however, Bowie joined with Eno, one of the founders of Roxy Music. For 12 of its 37 minutes, "Low" was magnificent. On tunes like "Sound and Vision," the icy, experimental instrumental' texture complemented marvelously the neurotic tension that is at the heart of Bowie's vulnerable, searching vocals. But most of the purely instrumental Side Two was simply too distant for pop audiences.

In "Heroes," Bowie again reserves most of Side Two for instrumentals. Where the mood of "Low" was tantalizing, the tone of "Heroes" is mostly withdrawn and bleak. It's a reflection, Bowie says, of Berlin itself.

"Berlin is a city made up of bars for sad, disillusioned people to get drunk in," he told a reporter in London. "I've taken full advantage of working there to examine the place... That's one of the reasons I was attracted to the city."

Despite the dreariness of much of "Heroes," there's some fleeting hope suggested in the album's title track: "We can be heroes/just for one day"

Rather than the skeletal lyric approach of "Low" Bowie offers more information, but not necessarily more illumination on Side One of the new album. "Beauty and the Beast," "Joe the Lion" and "Blackout" have common undercurrents of the doom and despair of a decaying society.

Unlike the bright instrumental textures of "Low," most of the instrumentals on Side Two are in a passive, semi-Gothic style best summarized by such titles as "Sense of Doubt" and "Moss Garden." The exception is "V-2 Schneider," a lively, infectious tip of the hat to Kraftwerk's Florian Schneider.

The problem with Bowie doesn't seem to be as much gimmickry as fluctuating pop interests that cause him to shift from style to style faster than his ability to master them. He seemed on the trail of a pop masterpiece in "Low," but "Heroes" ends up as one of his least arresting turns. On the whole, it is cold and unattractive.