As with anything else, the internet is rife with misinformation when it comes to guitar tablature. Case in point are numerous transcriptions of Lead Belly’s “John Hardy,” in which the tuning is indicated as down a whole step. But a quick listen to the folk-blues legend’s 1940 Library of Congress version of this traditional song reveals a low B, suggesting that the guitar is in fact tuned down two and a half steps, lowest string to highest, B E A D F# B.
This makes good sense, as it wasn’t really until the folk boom of the 1960s that 12-string guitars were commonly played in standard tuning. Before then, 12-strings had longer scale lengths and were tuned low and played as baritone instruments; Lead Belly and Blind Willie McTell being among the most noted players.
Though Lead Belly recorded his interpretation of “John Hardy” on a 12-string, it will also work on a six-string, whether down-tuned or in standard tuning. In the intro section, the guitarist plays a ten-bar figure that contains everything you need to play the entire song. He makes a simple I–V progression sound compelling with a melody based around compact open C and G chord shapes (sounding as G and D, due to the slackened tuning).
The guitar melody mirrors that of the voice, its bright major quality in tension with the song’s darker lyrics about a murderer who was hanged in the late 1890s. Note that Lead Belly never plays the 12-string part exactly the same way twice, and that his arrangement has a nonstandard form: like the intro, the first and sixth verses are ten measures long, but the other verses are 14. For those lengthier sections, just add a four-bar tag by repeating the last two bars of the intro figure.