I started to put some of these on Will topic, but decided I should start new one. For those that haven't heard these Icons of early country. The first group is earlier. The Latter in 40's with electric guitar, which I believe should get more credit towards the developement of Rockabilly down the path to rock, than they do.

http://www.youtube.com/watch?v=lROms0I5F0o&feature=related  (Memphis bound)
http://www.youtube.com/watch?v=LFhb9UGUUiw  (big river blues)
http://www.youtube.com/watch?v=CGF88o1NEZA  (careless love)

http://www.youtube.com/watch?v=XQhQbGz3fy4&feature=related  (frieght train boogie)
   http://www.youtube.com/watch?v=Bw0SC68MwjM&feature=related  (Tennessee choo choo)
http://www.youtube.com/watch?v=YUk9UDoVyKk&feature=related    (blues stay away from me)

here is a quote from the description of the first video in the list -

QuoteThe Delmore Brothers were one of the greatest early country harmonizers, drawing from both gospel and Appalachian folk. 

If you dig into it, gospel and folk - Appalachian folk - carried over from 'across the pond' were really the roots of what evolved into 'Rockabilly' etc.

Mix this with music brought to America from Africa and WA-LAH - you get Elvis.
Elvis learned to sing and developed his gifts in Church as did a high percentage  (most?) of those early 'stars'.
A list of those who began in Church is a Who is Who list

It seems to me today that folk does not get much respect -
real appalachian folk - 
Also, in my opinion , gospel - especially southern 'white' gospel, and  'black gospel'- the kind that influenced people like Elvis
does not get the attention deserved.

Most of the 'stars' of the 'Grand Ole Opry' first sang when in Church.

I think this is an historical fact that can be traced - without even getting into the 'spiritual' aspects.
I'm afraid many of the younger generation may not be aware of the roots.

It sounds to me that the harmony they have is based on 3rds ? Is that what you hear ?

- Larry

Larry just for the sake of discussion, most blues historians, not 100%, say the blues are truely an American art form, not from Africa.
Yes Africans, Blacks came up with them, but here.  The note bending may have come from them getting or trying to get semitones
that were included in some of thier scales from Africa but weren't available in the western scale. In early blues they might not have bent notes all the way up to next western step, but somewhere in between. 
So these guys, and gals were coming up with something new. With Jazz they blew everything out of the water. These were people with some truely original music. Some of them, in my mind, especially in Jazz were just musical natural genious's.  In a matter of  a couple three decades, they came up with the 2 true forms of American music that has lasted strong to this day.
   

yes, I understand (partially) the uniqueness of blues and Jazz -
I'm only suggesting that mountain Folk and gospel were a huge influence and that in my opinion they are often overlook when
discussing the roots of various styles.

I've not researched the blues back very far - but I'm guessing a lot of those black men from the south - first learned music when they were taken to church by their parents - and that as they grew they discovered the 7th cord -and off to the juke joints they went
with their new 'blues' style - that had its beginnings in the church.
Time after time when I read the bios of such famous artists - it says something like, 'his first exposure to music and the early development of his talents were in church'.

- Larry

The history of the blues isn't so well documented but I understand most agree it's something like this. The slaves field hollers were the source of the musicality of it. Banjo was the first instrument used. It is of African heritage. Think strings pulled across a drum.
With Banjo and later around the turn of century with guitars, the call and response of field hollers, and spirituals were done on guitars.
Call with vocals, response on instrument. The scales from Africa were different and didn't have the 3rd or seventh, nor the flattened
(minor) 3rd or 7th. The note was actually between steps. So between reaching to get that note and the emotion in the music, strings were bent. When people wanted to write it down there was no way to do so by conventional means so they settled for flattened 3rd and 7th. (I think the flattened 5th was later)  So the field hollers went straight into influencing development of the blues as well as into the churches.
To me the churches influence is not overlooked. In country or the blues. Especially in soul music, it's pretty well documented that it grew out of church music. Some church folks were pretty upset about it too. Going from church music to "the devils music".
Country music  like you said,  the singers consistently refer to learning to sing at church.  I really don't think folk music is over looked either. It's just some of the players.  How's this tie in with the Delmores?
The Delmore, to me, always had some blues mixed in their music, being exposed to them in the deep south. In the 40's to me, it took a more forward position and was put out front by the electric guitar. Mainly in the form of the boogie run. The first place I hear those boogie runs is with the barrel house black piano players in 20' early 30's. Jazz and swing players used it in the 30's.
The Delmore were white boys who put it out in a country context in down home type music. There were others as well like the incredible Aurthur(?) Smith.(He was a real guitar player, he could play country or jazz at lightning speed, once filled in for Django on a tour) But they were pretty popular and exposed a lot of people to it. Obviously North Mississippi and the Memphis area had this thing going on and many of the true originators I'll never know. But I just think that Electric guitar boogie run
in a country context had to be the seeds of Rock a Billy which lead to Elvis cashing in. (nothing against Elvis at all, he had the soul, incredible voice) He was in a position to carry it to the masses.  So that's my take. The history of the blues is what I've read. The Delmores being one of the paths to R&R are just my own observations and thoughts.

I think the history you mention is accurate -

QuoteBanjo was the first instrument used. It is of African heritage. 

..don't know if you saw if, but there was a very interesting documentary recently about

BELA FLECK going to Africa to discover the roots of his instrument. He visited many different locations.
It was really cool. He played along with them - picking up by ear on their unsual scales and meter, and
they marveled at Bela and his modern instrument - one man was able to play along - kind of - who could follow Bela ?

- Larry

What channel was the documentary on? Sounds good. Yes Bela can do it all. I've been following him since he was a teen. He play with a band called Spectrum which was mainly bluegrass and had ties to Kentucky so they were there a lot. But even then he's throw in a Jazz standard or 2. Appreciate but not crazy about what he does now. My favorite period from him was with Sam Bush and Newgrass Revival. Saw them several times while he was in band.  Yea I'd really like to see Bela on his quest thru Africa.

Found it Larry! Cool. It's playing at theaters now. Did you see it at a theater? I love the music they had on home page.
I would definitely like to see that for the music and the history. I knew the banjo came from Africa but that's about it.
I noticed it's playing around in places where I know folks on here live. If you go to screenings, it tells you where it's playing this month.
http://www.throwdownyourheart.com/

I saw a Mike Seeger Documentary on Banjos not too awfully long ago. He played all kinds of them including a Gourd Banjo.