Harmonicas are ... hooty, wheezy, twangy and tooty.

They're from the Old Country, but there's nothing better for American music, from blues to honky-tonk--and the fans are blown away

It's all the fault of "Peg o' My Heart."

It must have been around 1947 or 48 when I first heard this amazing sound coming out of our family's old radio. I heard it again and again, too, because that particular recording of "Peg o' My Heart" was destined to become, with some 20 million sold, the second-most-popular 78 rpm single ever produced in America, exceeded only by Bing Crosby's infuriatingly addictive "White Christmas."

The guilty parties were called the Harmonicats, I soon learned, and they were a trio--just three guys blowing into harmonicas. Unbelievable! How did they do it? It turned out I wasn't the only one asking that question because a few million other Americans did exactly what I did. We marched right out and bought harmonicas, hell-bent on discovering the place inside the shiny little silver toy where the sound was hiding.

There weren't many of us who found it. Within a few weeks I got pretty sharp on "Oh Susannah" and "The Red River Valley," but I never managed to achieve that magic sound. And there was something else, too, something very, very frustrating--I couldn't play "Peg o' My Heart." Not entirely, anyway--not right. It started out fine, and the lyrics washed through my brain as I tootled along: "Peg o' my heart I love you..." But then everything went to hell.

As soon as I tried to launch into the inspired poesy that followed (". . . Don't let us part, I love you, I always knooo it would be yooo") , the melody didn't come. I mean, the notes just weren't there. I sucked and blew and twisted and turned and went up above and slid down and tried every combination possible, but it was no use. Just when I aspired to reach the lyrics' immortal supplication, the note for that "Don't" part fled, causing me deep angst and introspection. Was I inadequate? Was I a lousy musician? (I was, but that's beside the point for the purposes of this article. Furthermore, my frustration continued as the lyrics maundered toward their Statement of Purpose: "Since I heard your lilting laughter, it's your Irish heart I'm after." Dammit, now I couldn't get the notes for "your" or "I'm." Where were those notes?

Not in my harmonica, as it turned out, nor anyone else's, for that matter--not even the Harmonicats', if they had been using the same hardware as me. After weeks of struggling to wring the missing notes from my instrument, I finally learned that there were two fundamentally different kinds of harmonicas: diatonic and chromatic. The diatonic (my original purchase) was what might be called the "My Country Tis of Thee" model, with only the basic seven-note scale built into it--the white keys, if you will. The chromatic, more complicated and more expensive, could, as its name implied, explore the full 12-note range of colors of more-complex music--call it the "Peg o' My Heart" model. The chromatic had the notes for Don't," for "your" and for "I'm" built into it--the sharps and the flats. The white keys and the black keys.

I eventually got a chromatic and triumphed, sort of, over "Peg" but never came close to the artistry or the sound of the Harmonicats. Years later I discovered why. To begin with, those three guys--Jerry Murad, Don Les and Al Fiore--were terrific musicians, and…