Robert Johnson

"In the first photo the world saw of Johnson, discovered in the late ‘70s by Steve LaVere and published in Rolling Stone magazine in 1986, the guitarist sits for a photo booth self-portrait, a cigarette dangling from his lip, a Kalamazooo KG-14 flat-top guitar in his hand. Zeke Schein, who works for Matt Umanov Guitars in New York City, says the identifying features of the KG-14 are “14 frets to the body, five dot markers, a single layer of binding inside the sound hole, and a black ebony nut," reads this article, by American Songwriter.

This was Robert Johnson's main guitar during his career. Made of mahogany. Discontinued in 1937, but recently Gibson has made a reissue model with better stability.

In a January 2012 American Songwriter article, in reference to the photograph:

"[Robert Johnson] is holding a 1929 Gibson L-1. Schein says you can tell from “the seven dot markers, an unbound fingerboard, and slanted ‘The Gibson’ logo.” This is the first full-body shot of Johnson, also discovered by LaVere. (Another photo of Johnson and his nephew from this same photo shoot is believed to exist.)

Ren Ferguson, Gibson’s master luthier, says the L-1 in the photo is probably a “studio guitar, not the guitar he actually played.” In 1994, Gibson licensed the guitarist’s name and began producing a Robert Johnson Signature L-1. Ferguson and his team tested a number of L-1s from that era, but ended up making a few modern updates to the original guitar style. Johnson’s L-1 would have been latter-braced, says Ferguson, while now they use X-bracing to give the guitar more clarity and balance.

On the guitars that Johnson and other bluesmen in the ‘30s were playing, Ferguson says, “The notes decay really quick, which is part of what we hear on those old recordings.”