Over a 50-year career, Dr John has grown from session man into the presiding spirit of New Orleans (he plays himself in the TV drama Treme). Tribal celebrates his legend with relish. A clutch of spooky swamp blues evoke his early days as the Night Tripper, elsewhere a classy band help the doctor drawl through strutting funk and anguished blues. "Big Gap" and "Only In Amerika" are angry political broadsides from post-Katrina Louisiana, and "Music Came" soars with help from local sax king Donald Harrison. Omnipresent is John's rippling piano, a style that reaches deep into Crescent City history. A heartening return to form.