Watch Dead & Company perform “IKO IKO” from the XL Center show that’s now available to stream. Based on the battle chants of the legendary Mardi Gras Indian tribes of New Orleans, this song first appeared in recorded form in 1953 as “Jock-a-Mo,” by James “Sugarboy” Edwards, then resurfaced under its current title as a smash 1965 single by the vocal group the Dixie Cups. It started turning up in the Grateful Dead’s repertoire in the late 70s and its irresistible groove was especially welcome at t