How was he out in uncharted waters? I don't really understand this. Jamerson was an awesome groove player, but so where a lot of upright players. So he did it on electric? Okay, that is to his credit. And of course he brought his own voice to the instrument, just like everyone does, but I think folks give him way more credit for "inventing" things that he didn't invent. As evidence, my next quote...
Not at all. James got his start on upright, playing jazz just like a thousand cats around him, and they played way more than roots and arpegios. This is the kind of thing I'm talking about. Jamerson took a lot of theory and knowledge that a bunch of other cats also had and applied it to electric. They brough jazz, soul and gospel to the table and out came Motown. But it's not like he was doing things musically that no one else had ever done when he played a non-chord tone. This is the kind of praise of Jamerson that I think is unfounded. Listen to some old James Brown. There's a lot of chromaticism in the bass playing, albeit on an upright. But it's super funky, rhythmic, and all the other things that Jamerson did on electric.
Jamerson helped define Motown and through that influence players for decades to come, and that's credit enough I think. I don't want it to seem like I'm slamming the guy cause I have a huge amount of respect for him. But when people make out like no one was playing bass before Jamerson, it just just feels like a slam to all the other players to me.
And like has been said here, he picked up the instrument (electric) when it was new, and many upright players didn't think it was worth anyone's time. He deserves a ton of credit for having the guts to do it anyway, and that really helps contribute to his lengendary status, which I readily think he deserves.