When I first waded into Greil Marcus’s book “The Old, Weird America,” a rambling meditation on Bob Dylan’s Basement Tapes and the entire inheritance of American music, I was skeptical, then frustrated, then just plain bored. For Marcus, every lyric and note that sprang from Dylan seemed to echo through the catacombs of American culture – from Harry Smith to Elvis, Memphis, Hank Williams, Lincoln, Melville, Andrew Jackson, black face minstrelsy, and the blues. I was dazzled (and dizzied) by the way he heaped up references, but remained ultimately unconvinced.

As I came to know more about Dylan (I eventually even made it all the way through Marcus’s book), it seemed less far-fetched (if still over wrought). Few musicians baptized in the rivers of American music ever absorbed so much as Dylan. For proof, one need look no further than Theme Time Radio, his new weekly one-hour program on XM Satellite Radio (Wednesdays at 10 a.m.).

The playlists – drawn from Dylan’s personal record collection – are the product of a lifetime of living music. Most of the songs come from the 1940s and 1950s – Ruth Brown, Buck Owens, Erma Thomas, Carl Smith, Dean Martin, the Prisonaires, Fats Domino – with occasional throwbacks to the 1930s and throw-forwards to the 1990s. (LL Cool J’s “Mama Said Knock You Out” was a pleasant surprise.) Between songs, Dylan discourses in his hushed, cracking voice on music or anything else that runs through his mind.

The experience is incredibly intimate, but never more revealing than Dylan wants it to be. He relishes the timeworn conventions of regional AM radio: call letters, corny jokes (“What do you do if you miss your mother-in-law? Reload, try again”), shout outs, and mail from listeners. It’s easy to imagine him broadcasting on a weak signal to all-night truckers passing through town on the Interstate. It’s also how he seems to imagine himself: He behaves as if no one is listening, which only makes it more riveting to listen to.

The loose theme of each program (“weather” and “mothers” in the first two weeks) allows for delightful nonsequiturs: from husband-and-wife duo the Consolers (“After the Clouds Roll Away”), to Jimi Hendrix (“The Wind Cries Mary”), to Judy Garland (“Come Rain, Come Shine”). His comments are equally scattershot, offering a glimpse into the weird musical webbing of his mind: “Okay, Judy Garland, just like Prince she’s from Minnesota.”

Dylan can give the most-moth-eaten vinyl collector a run for his money, but he delivers his trivia with aplomb. He runs down who covered a song, who wrote it, what the singer’s real name was, what political offices he held, and how much prison time he did. It’s probably written down on notecards, but it sounds like its all rattling down from the crowded attic of his brain.

Sometimes he gets pulled into the slipstream of his own aimless prattle: “Chicago’s known as the Windy City, but it’s not the windiest city in the U.S. The windiest city is Dodge City, Kansas. Other windy cities are Amarillo, Texas, and Rochester, Minnesota,” he says by way of introducing Muddy Waters “Blow Wind Blow.” He is acting out his vision of the doddering country DJ, but its no less charming for being affected.

Dylan’s knowledge of craft adds another dimension to his wayward commentaries. He praises the “dreamy underwater sound” of Pop Staples’ tremolo guitar on “Uncloudy Day,” then goes off on a riff about the difficulty of making that particular instrument behave. Sometimes it sounds as though you’ve tuned in to a conversation at the Music Legends Lodge: “Slim [Harpo] wrote a bunch of his songs with his wife Labelle. [Laughs.] Boy, I wish I had a wife like that, help me write songs,” Dylan says.

His love for the music is surpassed only by his love for rootsy language. The ironic pose and barbed wit of Dylan’s youth have rusted into a kind of folkloric eccentricity. He talks, in his practiced way, like an ornery centenarian with a plug of tobacco under his lip – like he’s been collecting minted phrases all his life. Jan Bradley’s “Mama Didn’t Lie” is “a many-fabled song by a honey-tone crooner.” Tommy Duncan of Whitney, Texas is “full of iodine and iron … all hydrogen and sulfate … no fatty acid in that.”

“If you think the summer sun is too hot,” he says apropos of nothing, “just remember: At least you don’t have to shovel it.” Virtually everything that comes out of his mouth is that quotable.

These dusty musings enchant the songs, and transform the way you hear them. Even familiar numbers like Sinatra’s “Summer Wind” are made anew. Just the fact that Dylan chose them makes you lean in close to listen for hidden significance and metaphysical reverb.

The reverse is also true: the breadth and mastery of American music Dylan displays as DJ elucidates his own body of work, and deepens our appreciation for it.