Alan Jackson kept the traditional flame of country music burning during the 1990s, an era when the parameters of the genre expanded dramatically. Jackson specialized in barroom ballads and hardwood honky tonk ravers, giving these old-fashioned sounds just enough of a modern spin to make them sound contemporary. He racked up an impressive string of number one singles, a streak initiated by 1991's "I'd Love You All Over Again" and spanning such modern standards as "Don't Rock the Jukebox," "Chatahoochee," and "Gone Country." Jackson broadened his purview in the 2000s, addressing...