Original: Gregory Lenoir Allman ( born December 8 , 1947 in Nashville , Tennessee ) , known as Gregg Allman ( sometimes spelled Greg Allman ) , is a rock and blues singer , keyboardist , guitarist and songwriter , best known as a founding member of The Allman Brothers Band .
Simplified: Gregg Allman ( born December 8 , 1947 ) is a rock musician . He was a member of the Allman Brothers Band with his brother , Duane Allman , which popularized Southern Rock in the 1970s .