Even when isolated from the gargantuan 26-disc box set Sony Music 100 Years: Soundtrack for a Century, the 51-track Country: The American Tradition is impressive. Columbia was one of the biggest labels in the early days of the record industry, as is evident from the beginning of this collection, which features cuts by Fiddlin' John Carson, Charlie Poole, Gid Tanner & His Skillet Lickers, and the Carter Family. What's more impressive is that the label -- and later, its subsidiaries -- captured the sound of each era. A glance at the featured artists -- Gene Autry, Bob Wills, Bill Monroe, Johnny Cash, the Byrds, Tammy Wynette, Willie Nelson, George Jones, Mary-Chapin Carpenter, and the Dixie Chicks are among them -- gives a sense of not only how the label developed, but how country music did as well. Some major artists are missing -- they didn't sign everyone, after all -- as are some trends, but the overall effect is overwhelming. This set traces the history of country music in the 20th century, offering a terrific educational experience while also being entertaining. It's a feat that's difficult to pull off, let alone by concentrating on one group of labels, which is why it's all the more impressive.