While there is no real objective way to measure soul, this statement is absolutely true. Other Dopers have pointed it out with many artists, but sometimes the only way to determine soul is by comparison. I, of course, have my own contributions:
Soul - Robert Johnson, Crossroads Blues (please note that Johnson is exceptionally technically proficient as well, and in a technique that would make most modern guitarists cry with frustration)
No soul - Eric Clapton, Crossroads Blues. This version just disgusts me. It’s the forerunner of all those blues cover bands comprised of fedora-wearing yahoos that think they’re playing the blues when they take an old standard, speed it up, and put a guitar solo in it. Ugh. Mr. Clapton is a very proficient guitarist, and I’m sure a nice man, but when it comes to his brand of “blues,” the boy has no soul.
No soul - The Beatles, Hey Jude. They just saw through the song in standard workmanlike fashion.
Soul - Wilson Pickett, Hey Jude. He puts this song to bed, and that insanely soulful musical break at the end, led by Duane Allman and backed up by the Muscle Shoals Rhythm Section, with Pickett soul-screaming fit to have a stroke, was, according to what I’ve read on it, improvised. Christ, now that’s soul.
Soul - Leonard Cohen, Hallelujah. Beautiful song, beautiful lyrics. Cohen wrote it, and he put plenty of soul into his recording of it.
No soul - Rufus Wainwright, Hallelujah. Again, he just sawed his way through it. No connection to the emotion or lyrics. Boring.
Zero f*cking soul - Bono, Hallelujah. Jaysus christ, you self-absorbed clown. What the f*ck were you thinking?
More soul than a white boy from New York should have - Jeff Buckley, Hallelujah. He makes you hang on every word, and that single note held at the end is just unbelievable.
The introduction of race into the “soul equation” is confusing too. You often hear that white people have no soul, or that white people stole black music and destroyed its soul. Poppycock. In terms of rock and roll, it is precisely the combination of white and black traditional musical forms which made it utterly transcendent and powerful. It was the union of hillbilly country music and delta blues, soaked in a history of racial uneasiness and emotion that made it so drivingly powerful. Same goes for what’s become known as “Southern Soul,” or “Memphis Soul.” It was essentially Southern black gospel music turned secular, and most of it was composed of a mixed-race band. Hell, when Paul Simon was recording Graceland* in Muscle Shoals in the 80’s, he specifically asked for “that same black band that made all those great recordings in the 60’s.” When he got there, he was surprised to find that the black band (The Muscle Shoals Rhythm Section) was mostly white.