THERE ARE CERTAIN ARTISTS whose albums I would never buy, yet whose live shows I wouldn't miss for anything. Rod Stewart is one of them.

On vinyl, the raspy-voiced superstar comes across as a stick, sugar-sweet pop tart, a Michael Jackson of the post-pubescents.

On stage, Stewart ranks with the best of the rockers. At 41, he radiates a youthful exuberance unrivaled by any of today's younger rock idols and oozes a raunchy sensuality that the typical heavy rocker in bulging pants would be hard-pressed to match.

I'm not speaking from the point of view of an infatuated fan (God knows, there were enough of those at the show in Dortmund Saturday). Anyone who has seen Stewart in concert, either solo or with Faces in the early '70s, knows that the man delivers.

More and more people are discovering that. too. When Stewart last toured Germany, in 1982, the audience consisted largely of the then-prevalent pop-disco breed, clean-cut folks in their mid-20s to late 30s who were content to sit back and watch.

These days, the dandy crooner attracts a diverse crowd that actually participates in the show.

There were the expected shrieking blondes last Saturday, the young men with the Rod Stewart spike dos and a few remnants of the disco generation. But there were also hippies who had come out of hiding, long-haireds, bikers, yuppies, families, lovers. teenies, oldies.

And Rod Stewart was the Pied Piper who led them all down the path of rock history. For nearly two hours, the 9,000-plus crowd sang and danced to some of the most popular tunes of the past 15 years.

Opening with the 1981 smash hit Tonight I'm Yours, Stewart lived up to the title and gave the crowd his all. Ever aware of his effect on the female fans, he strutted, danced and frolicked about the wide-open stage, a bit stiff in the joints at first, and deftly caught a gold necklace that had been tossed to him.

Hit followed hit as Stewart moved swiftly through a string of his older tunes, alternating raunchy rockers with romantic ballads: Hot Legs, Tonight's the Night, Passion, Young Turks, then a "heartfelt ballad for the gentlemen," I Don't Want to Talk About It.

More hits followed — You're in My Heart, Some Guys Have Aft the Luck, Infatuation, Sailing, Maggie May, Do Ya Think I'm Sexy — you know them well.

Also part of the fare were two ballads from his 18th (and latest) release, Every Beat of My Heart: the title track, currently rushing up the British charts, and Love Touch, America's 10th favorite song this week, according to Billboard magazine.

Backing Stewart on his trek through Europe is an excellent group of musicians, consisting of a three-piece horn section, three guitarists, a bass player, keyboardist and drummer. The flamboyant singer was gracious enough to relinquish the spotlight every so often to give the musicians a chance to show their stuff.

Bassist Charlie Harrison, formerly of Poco, deserves a mention for his impressive bass solo (you could actually dance to it) and drummer Tony Brock, a veteran of the Babys, performed an outstanding fusion of acoustic drums and drum machine.

Stewart, who earned the nickname "Rod the Mod" during the early '60s for the outlandish clothing he wore in London's R&B clubs and who later became known for his glitzy costumes and tight leopard-skin pants, has toned down his appearance somewhat this year.

But the Stewart fashion show still took place Saturday night. From a simple white denim jacket over black leather trousers, he switched to an oversized red and white striped jacket, followed by a belly-button-revealing white shirt. Still later Stewart appeared in a sky blue suit, limo-green sneakers and shades, his normally spiked hair greased back over his forehead.

But whatever his whimsy. Stewart's live show is definitely worth catching, maybe even twice. (He sure left the Dortmund audience wanting more as he left the stage without even an encore, allegedly to preserve his voice.)

In an interview with Germany's Bild am Sonntag newspaper recently, the singer claimed this tour will be his final one in Europe before he Settles down to become a "real father" to his kids.

And then we'll only have his albums.

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