Which band IS really America's Greatest (rock & roll band)?

The Doobie Brothers were/are as great live as in the studio, with hit songs inseparable from American pop culture.  

The "most American" band would have to be "Indigenous", three siblings and a cousin from the Nakota Nation, So. Dakota.  Listen to "Things We Do", their first album, 1998.  Blues guitar phenom in the style of SRV.     

I love the 19th Century lyrical themes from "The Band".  The historical ballads, the old-time sound, the small-town feel and their forlorn, back-woods style of singing are steeped in tradition, e.g., "Acadian Driftwood", "Cripple Creek", and "The Night....Old Dixie...", come to mind as spiritual and redeeming.  

Similarly, Robert Hunter's lyrics with the Dead often speak of Appalachian folks, oppressed laborers, miners, winos and hoboes--but also of lonely burdens and spiritual rescue. With lyrics such as "I live in a silver mine and I call it Beggar's Tomb"; "Goddamn, well I declare, have you seen the like? Their wall are built of cannonballs, their motto is 'Don't Tread On Me'"; "Tumble down shack in Bigfoot County, snowed so hard, the roof caved in"; "Now I don't know, but I been told, if the horse don't pull you got to carry the load".  And yes, the GD could sing well--better in different periods of their long history.  Listen to "Jack Straw" from Europe '72 for a live example.