Okay, I wasn't around when this was released. So I'm not going to even pretend to know what impact it had on culture or vice-versa. I'm not old enough to remember a lot of jazz landmarks, but I can seriously acknowledge that the "Electronic Sonata" does not sound dated. I suppose some passages sound more late-60s than others (the wah guitar screams of the one they called Jimi), but they are few and far between and they do not detract from the overall picture of what's going on here.
One surprising thing about the old avant-garde is their ability to make noise that doesn't sound like antiquated mish-mash. As the "Electronic Sonata" alternates between its groovy movements built around a piano or electric guitar vamps and it's bottomed-out ambient and spacey counterparts, the latter sound so much more mysterious and contemporary than the former. I guess that's to be expected. But to not come across as embarrassing over forty years later? That's something.
And these weirder moments do not violently vie for your attention. George Russell used his skills as a composer to put pen to paper and summon a nebulous cloud of sound that sounds like little else long before Brian Eno had a solo career. No wonder he was a MacArthur fellow.
To be honest, I got this because the download price was so good. And I had read that this album is something of a touchstone in free jazz. I'd heard lots of free jazz and avant-garde before this, but this is something different altogether. It's a mammoth. It behaves differently from all the other experimental stuff being made at the time, and it's a very challenging listen likely to completely wear you out.