The plaintive, almost human-sounding wail of a slide guitar has been recognisable as one of the hallmarks of American vernacular music since the early 1900s — whether being played by pioneering blues guitarists like Robert Johnson and Blind Willie Johnson, in the country and western idiom by the likes of Roy Acuff and Jimmie Rodgers, or even Hawaiian style by Roy Smeck and Sol Ho‘opi‘i. Let alone modern-age purveyors such as Ry Cooder and David Lindley.

Yet it took a seemingly unrelated and concurrent innovation in packaging to create a lasting effect on both the sound and the style of the slide guitar player for a century and counting. That would be The Coca-Cola Company’s introduction of its now-classic contour bottle. 

Musical Ingenuity

Since the turn of the 20th century, guitarists have been tamping down the strings of their instruments to alter its sound with a plethora of handy objects, including penknives, lighters, animal bones, and the necks of a variety of decanted libations both soft and hard. So why does the image of the curved green neck of the contour Coca-Cola bottle endure as the sonic and aesthetic standard for slide players?

Bill Combs, vice president of the Coca-Cola Collectors Club and an accomplished guitarist, speculates with the expertise of a man who has been amassing Coca-Cola memorabilia for three decades, that the use of a slide fashioned from the iconic “hobble skirt” bottle began the first day a slide player purchased a Coke.

“Guitar players are pretty resourceful,” Combs points out, “and when something is readily available and, most importantly, costs five cents — which includes a refreshing drink — they used it. 

“What makes an entire Coca-Cola bottle — or even just the neck — a popular thing to use is the same reason we celebrate the anniversary of the bottle today,” Combs continues. “Everyone immediately knows what it is. If you are in the first, 10th, or even the 20th row, you'll recognise the contour bottle or any part of it.”

The Coke bottle’s ubiquity and its pleasing and recognisable aesthetics certainly give it an advantage over, say, a pork rib, but there’s something that further explains its initial proliferation and its lasting appeal. 

Howard Markman, the Baltimore-based guitarist for such bands as Freewater, Disappear Fear, and his current combo, Palookaville, has been pressing bottleneck to guitar neck since his late teens, after beholding blues masters Bukka White and Hound Dog Taylor as they plied their trade at a music festival in the late ’70s. For him, at least, the appeal is quite personal, though his words hint at universality.

“The glass of the Coke bottle has the right density for the tone I like — not too bright, not too dark,” says Markman. “The curve of the bottle’s neck works well with the radius, or the curve, of several of my guitars. And it fits my finger.”

Creating Sound

Some musicians have taken the Coke bottle to an even greater instrumental extreme: In the 2008 documentary It Might Get Loud, Jack White, whose sense of history and creative curiosity are well documented, uses the entirety of a classic contour Coke bottle to craft and electrify a rudimentary guitar known historically as a “diddley bow” – all in a mere matter of minutes. 

Suffice to say, just as Jack White owns a store-bought guitar or two, even those players who wish to visit the authenticity of slipping the hacked-off neck of a genuine Coke bottle on their fretting finger will sometimes utilise manufactured slides. “Being able to walk into a store and pay $10 for a slide is a whole lot easier than trying to cut one yourself,” Markman says.

Nonetheless, Markman regards using a sawed-off Coke bottleneck as bringing him closer to the original source — specifically, the legendary blues guitarists who innovated and mastered the form. “Using what they used can get you more in touch with that feel,” he says. “Also, there are sounds you get from certain bottles that is just different than you get from modern glass or plexiglass slides. It’s just a matter of finding that bottle that gives you the sound you want.” He does point out that he also has the option of patronising small manufacturers who will vend slides made from actual bottles. 

As for Combs, he makes it abundantly clear what characteristics he seeks in a prefab slide: It's got to be “as close as the neck of a Coke bottle as possible,” he insists, adding, for good measure, “Are you really asking that question?”