i just trying to point out that the guitar creates the sound... the amp amplifies the sound... the efx (sustain, compressor, delay, chorus, etc) effects the sound...
there are 3 things that are actually going on...
but it all starts with the guitar itself...
It even goes deeper than that. Guitars are real finnicky instruments. Everything from the player, to the strings, to the pick, neck position, to the Guitar pickups vs. acoustic, wood, Amp/direct/micing techniques plays an impact on the sound. A lot of the sound also comes from the players "playing style".
Guitars aren't like digital synths, where they sound the same if you turn it off for a year and play it again.
Different types of picks, strumming position, up stroke, down stroke, finger picking, palm muting, vibrato style.
I'd say most of R&B guitar is based more on technique than what type of amp you are using.
The guitar type will make a difference as well though (Strat vs. Tele vs. Hollowbody vs. Acoustic).
But usually most R&B sounds will be more on the clean side. And a lot of styles use acoustic guitars even where mic and playing technique is more dominant.
Most producers will have a dedicated guitar player on hand to add to their tracks.
But I think most companies are scared to produce a great guitar library because of the work involved and the harsh amount of negative critcism they will receive because everybody has their own idea of what a good guitar should sound like.
You can put 10 people in a room with a great piano and probably only 1 person will give it a negative review.
A guitar will be criticized much more harshly because of the wider range of sounds it can produce.
It seems like every guitar library that comes out always have way less agreement whether it sounds good vs. a piano or drum library.
