Last August 16 marked the anniversary of the death of a monumental figure in American musical history. Rising from poverty, this guitar-playing son of Mississippi proved such a huge talent that successive generations couldn't help but acknowledge their debt to him. Not even his untimely death could -- Wait a minute. You thought I was referring to Elvis Presley? Actually, I just pulled one of those journalistic "gotchas" that make steam come out of Ross Perot's ears. Elvis fits the above description. But the musician I had in mind was Robert Johnson, the legendary King of the Delta Blues who, like the King of Rock and Roll, died on the 16th of August (in 1938, 55 years ago this summer). One other personal fact the two men share is chart-breaking success in death. In Robert Johnson's case, the success was particularly stunning: Three years ago, a 2-CD box set of his complete recordings went gold and won a Grammy for the best historical album of the year, no doubt helped by reviews that raved about the power of the music and the pristine sound of the remastered original 78s. Perhaps not coincidentally, the past couple years have seen a resurgence in the blues and acoustic music in general, as evidenced by MTV's popular "Unplugged" series and the Grammy triumphs of blues-rockers Bonnie Raitt and Eric Clapton. These strike me as isolated developments, though. Despite its historic role as a precursor of jazz, rock and country and its intrinsic artfulness, the blues seems by and large to continue to be an unappreciated and misunderstood musical form. The specific category of blues I'm discussing here isn't electric Chicago blues or the MTV-friendly versions of the genre as performed by Ms. Raitt, Mr. Clapton and others, but rather the foundation of those forms -- what's known as the country blues, as practiced and perfected up to about 1945 by folks of little means (usually black, male, Southern and rural) accompanying their own vocals with acoustic guitars. For those who were raised on the Top 40, the gruff directness of some of the old blues masters can take some getting used to. Many people would rather not bother trying at all, deriding what they see as the amateurism of the players and the depressing nature of the music. My response to the first argument is to cite the old maxim that less is more. Indeed, blues players like Blind Blake, Willie McTell, Lonnie Johnson, Skip James, Gary Davis, Charley Patton, Bo Carter, John Hurt, Willie Johnson, Son House, Scrapper Blackwell, Tampa Red and many others crafted three-minute gems of such exquisite dexterity that aficionados today still attempt to decipher them. As for the rap about the music's being depressing, well, it is called the blues. However, one of the greatest misconceptions about the genre is that its themes are exclusively sad. Not so. The range of subject matter and emotions found in the blues is as broad as that of any other musical form. Culture critic Martha Bayles addresses this point in a piece on the blues for the current Wilson Quarterly magazine. " . . .'[H]aving the blues' is not the same thing as 'playing the blues,' " Ms. Bayles writes. "The former refers to a negative state of mind, such as loneliness or grief, anger or fear, disappointment or jealousy; the latter, to the art of leavening, tempering or (possibly) transforming such a state." Still, the blueness of the country blues, as well as its association with poor rural blacks, prevents it from getting the respect it deserves. Jazz, in contrast, moved uptown and acquired an urban sophistication that's light years from the farms and backwaters of Mississippi. Jazz is revered, and deservedly so. That's not to imply that the unjust living conditions forced on many of the old blues musicians should be romanticized in any way. Far from it. But I think the origins of the music help explain why a lot of people, especially blacks of later generations, want nothing to do with the country blues. They hear it and think of bad times better left behind. Certainly that reaction is understandable. And yet it fails to pay proper homage to the bluesmen and blueswomen who, in creating intensely personal musical expressions from their experiences, gave birth to an art form as beautiful and distinctly American as any produced in this country. The observation has been made that Mississippi's two great contributions to world culture were William Faulkner and the Delta blues. More Americans should be aware of that fact -- and proud of it. Patrick Ercolano writes editorials for The Baltimore Sun.