I would venture to say they are on more hit records than any other band. And a wide array of styles too.
FAME studios has held a mystical place in my head ever since I bought my 1st real albums: Otis Redding Live in Europe and Allman Bros at Fillmore East, followed quickly by Duane Allman Anthology. I was still shocked to see just how many of the quintessential records of American culture were recorded there...many with the Swampers. In a tiny town in the middle of nowhereland of Northern Alabama....probably an area most New Yorkers would vote to destroy without thinking lol. I can picture young artistically principled music lover Duane leaving L.A. disgusted and finding his way to pitching a tent in the parking lot of N. Alabama
Boy did Rick Hall miss the boat on him! I guess its only human to underestimate a kid sleeping in your dirt parking lot in the middle of nowhere though.
The South has a great tradition of everyone playing instruments and singing together...everyone, at family events, with friends, etc. Hence they get good , pass the torch, and EXERCISE the musical traditions like a stew...LOTSA folks are good, not just the 1 person in the family who plays professionally e.g. Its probably related to the self-sufficiency nec'y to live (sanely) in the country...if you cant go down the street and see a movie or a show (or afford one) you make one yourself. Similar circumstances in poor neighborhoods before 95% of the country got cable (take a look at shocking footage of the devastated South Bronx during the Carter years to see where Rap music began). This is being lost as the culture changes and technology takes over our leisure time, in the South, in Ireland, probably even in Africa. The ignorant or exaggerated caricatures of the South re: education or universal racism have always bothered me, and they are almost always made by people who have never spent more than 1 week at a time in the South; and they insinuate that the same issues were/are not serious problems in other areas of the US. Black music was popular with the public in the South years before it was respected by the general public in the North e.g. Maybe the dichotomies, paradoxes, and richness are the reason so many classics have the South as subject matter.