Very nice map.

Historical comment only. I first listened to this music in the late 1970s. One big change in the story, over time, is how few people trace the sound to Hendrix now. (Not this map in particular. Metal fans I know would agree with the map.) I think (?) a common current viewpoint is that Led Zep [!?] was foundational but the genre really started with Black Sabbath and Judas Priest.

Which, definitions change. But in 1977 I listened to Purple Haze and, sure, it was "Psychedelic Rock" as indicated on the map. 100%! But it was also almost definitionally metal. Forty-nine years ago, I mean, not today.

[!?] I love Zeppelin. But I would have been laughed out of high school if I'd compared them to metal, or claimed they were even hard rock.

That’s interesting. Somehow my brain never really put that together. He was obviously ripping heavy blues and innovated more than anyone before and arguably since. Thanks for adding him into my mental Metal flow chart.

For me I would always say that somewhere between 68-71 metal was being cooked up by Black Sabbath in Birmingham, Motörhead in London, Pentagram in Virginia, and Blue Cheer in San Francisco. Obviously Hendrix’s influence would be most obvious with the latter.

I started learning guitar in 2006 and my guitar teacher pointed out how metal originated from Hendrix's sound. I always thought that was common knowledge

In my opinion Hendrix is to electric guitar what Beethoven was to (Western) harmony. All contemporary lines go through him.

One thing to note though is that Hendrix had a very short career in which he lived/performed in Nashville, the Chitlin' Circuit, Greenwich Village, and London. On top of being an incredibly proficient/creative guitar player he also had an incredible ear and picked up sounds/techniques/songs from everywhere he lived and with everyone he played with.

Part of why you can trace the evolution of guitar playing through Hendrix is that on top of his records being popular and everyone learning those tunes as a first/second year student, his own musicological background was a fusion of the major songwriting movements of the 1960s that spawned modern blues, pop, funk, fusion, rock, and metal. It's easy to see Hendrix as an influence on modern music because he was a magnet for players of all those genres.

What's interesting about Hendrix is that he is "an artist you listen to" instead of "an artist who an artist you listen to, listens to" from the same era like Albert King or Joe Pass.