SAVANNAH, Ga. (AP) — Gregg Allman, a survivor of tragedy, knew the blues musically and in a painfully personal way.Raised by a single mother after his father was shot to death, he idolized his guitar-slinging older brother, Duane, and became his musical partner. They formed the nucleus of The Allman Brothers Band, which helped define the Southern rock sound of the 1970s.Their songs such as "Whipping Post," ''Ramblin' Man" and "Midnight Rider" laid the foundation [...]