This exhaustive reference book isn’t for everybody, a point driven home by its relatively steep ($49.95) price tag. But for obsessive chart-watchers, the latest edition of the invaluable Hot Country Albums compendium is worth its weight in gold. Inside you’ll discover a wealth of fascinating chart statistics drawn from the archives of the esteemed trade magazine Billboard, numbers that—in their own way—tell the story of country music’s evolution over four decades more honestly and objectively than prose ever could. (Available at recordresearch.com.)