A Bob Dylan show does not sound like a Bob Dylan greatest hits album. Nor should it.

Yes, he plays mainly songs from his albums, even plays his hits: "Highway 61," "Just Like A Woman," "Like A Rolling Stone," Blowin' In The Wind," "All Along The Watch Tower," "Tangled Up In Blue."

But Dylan makes music, doesn't recreate hits. The songs he wrote, that we all know, are now the skeletons on which he builds new riffs, tempos, beats, shuffles, blues. Think barroom. Dim lights. Sometimes dark. Sometimes eerily uplit. He's not in the spotlight, not even center stage.

He's off to the side, but it's his band. Two guitarists, bass player, drummer, steel player -- they don't face the audience as much as they face Dylan, watching them from off to their left. They watch him carefully, like geese watching the lead bird. Afraid to take their eyes off him. Miss a move, they'll be off course in a flash.

Reviews of Dylan's latest CD, "Tell Tale Signs," note how the songs are alternate takes from his recent past. But reworking his music is what Dylan has been about for years. That's especially what his live shows have long been about.

Like a jazz man, Dylan uses his songs to launch from. Charlie Parker reworked the Gershwin's "I Got Rhythm" and created the language of bebop, a genre that continues to be reworked by successive generations. Dylan -- he reworks Dylan. Yes, we recognize the chord changes. We know the lyrics. We can sing the melodies, the original ones. Other musicians, they still play Dylan. For Dylan, Dylan is just foundation for newer creations.

In Dylan's hands at the Riverside Thursday night, we don't always know the song, at first. And that's just fine. Dylan is a student of American music, as fans of his amazing, weekly XM radio show, "Theme Time Radio Hour, With Your Host Bob Dylan," have long known. A surprisingly erudite, wry and snappy DJ, Dylan tells radio listeners short stories about each song he spins, songs representing an amazing depth and breadth across the American music spectrum. You feel his passion for the songs he selects, the songs of America.

So in concert in Milwaukee, when he reworks "A Hard Rain's A-Gonna Fall" into something jaunty with a triplet feel, you don't mind missing the old version you've heard on the radio ten thousand times or more. "Highway 61," originally bluesy, is even more so Thursday. His voice more sinister than ever. The melody reduced to just a few notes.

But the notes he sings, or the occasional harmonica he blows, aren't about melody. Perhaps they never were meant to be. Today they're about rythem. Another instrument on stage. The inventor and driver of the vehicle, but one of many hands powering that vehicle.

Dylan and his men tonight aren't folkies, but we have known not to expect folkies after he hit the road so long again with what was to become The Band, touring famously to boos and cries of "Judas" for abandoning the folk orthodoxy he solidified. Tonight his band is dressed in non-identical black leather jackets, black shirts, black leather pants, black hats. Dylan is in black, but in a suit coat, silver buttons, buttoned up, additional silver buttons or amulets on his jacket. A violet shirt. A tie. Pants with a tux-like stripe down each side. And a white, wide-rimmed hat, flat top. Lithe.

Singing into a vintage-style microphone, the kind from old radio shows or the big bands in ancient movies. Standing all night, behind an electronic keyboard that sounds like an organ. No guitar for him tonight. Word has it his hands just can't play one so well any more. But he's swaying now and then as he plays the keyboard. Singing like a jazz man. Leading the band with the slightest movement.

The main who invented modern folk music closed his show with a re-invention of "Blowin' In The Wind." Gone is the solo folkster from 1960's black-and-white photographs, singing, playing acoustic guitar, blowing a harp hanging from his neck. (Oh where have you been my blue-eyed son?) Instead, we hear a swinging, almost gospel version of "Blowin' In The Wind." He's playing organ, a bit like Al Kooper on "Like A Rolling Stone."

We know the song one way. We can sing that version in our sleep. But tonight, a packed Riverside loves it just as much a different way. Some of us maybe more. Because he's making music, not playing greatest hits just the way he played them on some fateful days in recording studios a long long time ago. He's still, as he's been introduced live for a zillion years, by a sonorous voice, theatrically, almost ironically: "Columbia recording artist Bob Dylan."

Key word here: Artist.