Parts of it are a little clunky, like that opening. It's a tad redundant but is the kind of thing that's so natural to preface something with, I generally find myself doing something similar to get started and then going back to cut it out later. There are one or two other bits that didn't flow very well either, such as the placing of this line: 'My blues collection is limited almost exclusively to the works of Blind Willie McTell, Blind Willie Johnson, and Robert Johnson, and I wish to discuss them in a series of three articles.' It jars where it is now.
However, these are minor quibbles and the kind of thing that you'll lose with time in any case so not something to be too worried about. The meat of it, both what you're trying to say and the way you express it, is very good and one of the few kinds of music writing I enjoy. You describe what the pieces evoke for you and I was particularly interested in the imagery you present as being created when listening to them. I also thought this was interesting, and nicely put: 'The man howls out from the despair of the solitude inflicted on him by his blindness, he yells out to a Lord he can not ever see and whom he has not yet heard. These are not hymns, they are desperate prayers of longing for salvation. I am not religious but the power of this humble struggle does not escape me.' I would have liked to see you say more on that.
In short, this is great and I'm looking forward to seeing what you write about Blind Willie McTell.