David Cantwell and Bill Friskics-Warren's Heartaches By The Number echoes Dave Marsh's book-length list The Heart Of Rock & Soul in that both comment on a massive body of popular songs, and both are best read as extended, purposefully ordered arguments. Heartaches works fine as a reference, or as a flip-back-and-forth "snack" read, but consumed cover to cover, it's almost flabbergasting. The authors begin by dismissing any definition of "country music" as an identifiable sound, instead looking at the genre as a set of recurring themes played in a style determined by cultural consensus. They have no problem praising pop-country divas Faith Hill and Shania Twain, since both represent the state of the genre in their time, and they have no problem including Otis Redding and Creedence Clearwater Revival, since the country-music charts have been dominated in the past by equally raw R&B and rock. Though Heartaches is ordinal in a loose sense, the 500 singles cited fall into place mainly by how they relate to each other: Songs about trucking, drinking, death, obsessive love, or other motifs appear in short sequence. Cantwell and Friskics-Warren position them as a dialectic, with one song commenting on the other and working in concert to tell the country-music story–one of racial cross-pollination and earthy tales of everyday life. Each entry is a performance unto itself, and for the most part, the authors spur each other to go deep, grappling with historical context while laying down plainspoken, evocative descriptions of the songs. They have distinctive, complementary voices: Cantwell is the fervent enthusiast, making the case for the sensual pleasures of his favorites, while Friskics-Warren is the incisive analyst, decoding secret messages. Sometimes he overdoes it, reading too many songs as being about class conflict, and thereby giving the rich too much credit for being on the blue-collar mind. More apt are his descriptions of how numerous country songs contemplate the "feelings of stuckness" that weigh on working folk. Amid all the well-researched mini-biographies of stars and sidemen–and all the celebration of how it feels to grip tiny pieces of authentic American folk art between the thumb and forefingers–Heartaches By The Number earns its place among the essential texts of pop-culture criticism for the way its authors focus sociopolitical musings through the precise confines of the music they've chosen. Like the best country songs, the book's entries miniaturize the problems of the world, making the universal personal, comprehensible, and even exquisite.