Robert Johnson is absolutely fascinating, and the lore around him only adds to that fascination. He is one of The Greats™, but wasn't always considered so.
His recordings were made in the mid-1930s and didn't lead to any major acclaim until after he'd died. While he was alive he did have a following, especially because many believed that he went down to the crossroads and made a deal with the devil for his soul to become the great guitarist that he was. I didn't know about it until I'd seen a Netflix documentary about him, and it's stuck with me ever since; the mystery around how he became so good just makes me appreciate him more. To be so good at your craft that people think the only explanation is black magic is amazing to me.
There was a lot about him and his life that was not known when people started getting really into him in the 1960s. His recordings were transferred from the original label to Columbia when they bought it, and Columbia decided to release an album in 1961. Public records revealed little about him except for a couple of marriage certificates and his death records. It took until the 1970s for anyone to even find photos of him, eventually obtaining 3 from his half-sister.
I got to listen to his complete recordings during an earlier iteration of the top album challenge, and it is one of my favorite albums. It's definitely a must-hear whether someone is a major blues fan or not. Without Robert Johnson, shitty humans Eric Clapton and Jimmy Page would have had a lot less material. All the English rock bands during the mid-60s were influenced by the early blues guitarists, covering their songs and imitating their styles. Hell, Led Zeppelin even stole his lyrics for songs they actually wrote.
RIP Robert Johnson, my favorite member of the forever 27 club.