One of the things that has traditionally seperated Soul/R&B has been a greater tendency to "work" the song, i.e. to take structure for granted and then to build in the rythmic and melodic spaces around and between it, as opposed to the more straight-ahead rock/pop approach of delivering the melody and chords clearly and forcefully.

This can be applied to any type of music, and usually makes for greater interest, subtlety, and richness. Look at classical or jazz.
This idea of soul, though, in the Al Green, Aretha Franklin sense...more or less a cultural happening in the continuum of American pop history. Like the rock or jazz or country of that period, it just can't be done again, and that is how it should be. The core elements involved are still as vital as they ever were, and in some cases, more needed now than ever, but trying to 'get' any particular essence like that only results in contrivance. They can inspire us, of course, but the dynamics of our world right now are very different, and to make relevant art, that's what has to be driving us. Tune into what's going on in our lives and find a passion to make this a better place...then you'll have soul.

As usual I find yep's comments insightful.
I plan to try an experiment this weekend. I wonder how a song would sound by taking a rock drum pattern ( will use one from EZ drummer) and removing the "root" hits. Then try to build around it with what yep is talking about.
Has anyone tried this yet?

Well, sticking my neck out, I'd say that the vast majority of uptempo soul & rnb these days wouldn't stray too far from 4/4, as it would be hard to dance to. Ballads would be a different matter I guess.

I'm glad we seem to have moved on from every song having that 'Funkydrummer' James Brown sampled beat though...

What sort of chords? Any that suit the melody would be the glib answer; I have heard some stripped down acoustic versions of fairly simple soul songs lately, given new arrangements and with some delicious chord voicings. It's all open to interpretation.

It depends on the artist also I suppose, you'd probably find more complex chords in something by Alicia Keys, Corrine Bailey Rae or George Benson, who lean towards the jazz end of the spectrum, than perhaps in Justin Timberlake's work.

Plenty of sheet music on the 'net, why not check some out?

I'm glad we seem to have moved on from every song having that 'Funkydrummer' James Brown sampled beat though...

ahh...1997! Those were the good old days. lol.