Meet Shirley Q. Liquor, the middle-aged, overweight, Ebonics-speaking black persona of a white comedian, Chuck Knipp, who has been leafleted in Manhattan as “racist, classist, and misogynist.” Adept at skewering “ignunt” folks of all colors, Shirley is a character who could easily pop up in the repertoire of many a present-day black comedian. But as John Strausbaugh writes in his fascinating but uneven new book about the impact of blackface minstrelsy on American popular culture, “Black Like You” (Tarcher, 372 pages, $24.95), the color of the comedian makes a difference. Because of its painful history, “blackface is taboo, and a White comedian making jokes about Black people will be banned.”

Yet Mr. Strausbaugh defends “cultural magpies” like Mr. Knipp. As he explains, blackface minstrelsy was the dominant form of popular theater in 19th-century America, and it definitely did trade in demeaning racial stereotypes. But it also introduced white (and European) audiences to at least a semblance of black music, comedy, and dance. And after the Civil War, when minstrelsy was opened to black performers, it became a unique training ground for their talents. As Mr. Strausbaugh’s lucid, fastpaced account makes clear, it is impossible to understand the popular culture of the 20th century, never mind the 21st century, without first understanding blackface minstrelsy.

Studded with apt quotations and nicely pitched anecdotes, the first 300 pages of “Black Like You” survey both the good and the bad sides of blackface — the grossly racist and offensive, and the genuinely comic, musical, even subversive. For instance, Mr. Strausbaugh recalls a “stump speech” by the famous minstrel Lew Dockstader, in which the performer, a white man corked up to look like a caricatured black man, poked fun at another white man, Teddy Roosevelt. Imitating Roosevelt’s description of a make-believe club for his mendacious political enemies, Dockstader intoned: “While I am not a member of this club, it was founded, confounded, and dumfounded by me. Every member on its long rolls was proposed, seconded, and unanimously elected by an overwhelming majority of myself. … Its purpose [is] to provide an institution where distinguished stiffs — after I have laid them out — can LIE in state.”

With swift strokes, Mr. Strausbaugh traces the transition to vaudeville from minstrelsy, when at the turn of the last century massive immigration filled the popular stage with a slew of new ethnic stereotypes — not just the blackface staples of countrified Jim Crow and citified Zip Coon, but also “brawling Irish, wheedling Jews, oily Italians, thick-headed Germans, inscrutable Chinamen.” Here Mr. Strausbaugh waxes eloquent on how, before “the rise of multiculturalism and identity politics encouraged everyone to be ‘offended’ by everything,” newcomers to America simply “presumed that earning a spot for yourself was a rough-andtumble procedure. It took a thick skin and a sense of humor.”

Yet as Mr. Strausbaugh adds, this was true “for everyone except Black people. … For newly arrived immigrants, mixing it up in vaudeville theaters was one part of the process of becoming assimilated and recognized as White. … Blacks were still outcasts.” It is debatable how quickly all the groups Mr. Strausbaugh mentions became “recognized as White,” but one can hardly dispute his larger point, which is that blacks remained largely segregated “until they forced their way in through the civil rights movement.”

But if blacks “forced their way in” during the civil rights era, then presumably the racial dynamics of American culture would have changed at that point, and instead of the minstrelsy model, in which powerful whites amused themselves at the expense of powerless blacks, post-1960s popular culture would have followed the vaudeville model, in which all groups mix it up on more or less equal footing. This is an important moral distinction that Mr. Strausbaugh himself makes when treating topics from the past. But he gradually loses sight of it while tracing the legacy of blackface through Broadway, “Negro-dialect” literature, “race” and “Blaxploitation” movies, the collectibles known as “Negrobilia,” the 1996 Ebonics flap, and finally hip-hop.

Hip-hop appears in the final chapter, and Mr. Strausbaugh’s treatment of it leaves much to be desired.To be fair, he does compare it with minstrelsy — a comparison, verboten just a few years ago, that is now commonplace among hip-hop’s critics, especially such black critics as Greg Tate, Debra Dickerson, and Stanley Crouch. Mr. Strausbaugh quotes these and others, but then reverts to the vaudeville model, basically defining even the most racially demeaning rap as good old rough-andtumble, an updated form of clowning and mugging that in essence helps the world to become better acquainted with black Americans. And he dismisses the recent criticism as “moral panic”on the part of “civic leaders,the cultural elite and the upper classes” — y’know, all those uptight prisses who’ve been fussing and fuming since Day 1 about the sexy good times enjoyed by the poor, especially the black poor,. Why the poor are assumed to have no moral concerns of their own, he does not clarify.

Just as vaudeville degenerated into a form of burlesque theater centered on titillation, so has a certain strain of rap degenerated into what one veteran of 1990s hip-hop calls “a sad marriage with pornography.” The lyrics of many “crunk” rap songs, for example, are nothing but variations on the old strip club chant, “Take it off, take it all off.” Of course, nowadays most of it has already been taken off, so tracks like “Get Low,” “Lean Back,” “Tilt Ya Head Back,” “Flap Your Wings,” and “Ass Like That” urge ever more explicit displays of wagging behinds and jiggling implants. One wonders why such urging is necessary. If acres of faceless female flesh are not enough to excite crunk fans, then perhaps they should see a therapist — or better still, give it a rest. Even Groucho Marx took his cigar out of his mouth once in a while.

Burlesque was not vaudeville, and likewise, this stuff is not hip-hop. Because pornography’s spouse in this marriage is the old trope of black bestiality and stupidity, well-documented by Mr. Strausbaugh in his chapter on “coon songs,” a better name might be “coonporn.” Coonporn is now being exported to the rest of the world in massive quantities, including to remote places where people have never seen a black American, except perhaps a soldier. Not surprisingly, this creates perceptions that can come as a shock to black Americans traveling abroad. Consider this comment by Darius James, a Berlin-based writer who, as it happens, also wrote the epilogue to “Black Like You.”

Describing the experience of hearing coonporn in Berlin, Mr. James writes: “I’m not condemning gangsta rap, or rap in general, or sex and violence. I’m talking about some drunken and blunted fool spewing abusive and dysfunctional bull— that’s not about anything at all, except being abusive and dysfunctional. And a lot of young Germans listen to this sh— because it’s supposed to be hip, not really understanding what’s going on in the lyrics. If they knew, they would puke.”

Memo to John Strausbaugh from Shirley Q. Liquor: If this stuff don’ make you puke, you jus’ ignunt.

Ms. Bayles last wrote for these pages about HBO’s “Elizabeth I.”