The Complete Book of Chords, Scales, and Arpeggios for the Guitar Book

Given the ambition of Taruskin's series (of which this is the fourth of five volumes), this 800+ page volume is the most ambitious of them all and likely the most important. Covering the first half of the 20th century, there are numerous challenging concepts introduced about the intersection of music with the emerging field of psychology as well as the idea of the composer as a public intellectual, begun in the more modern sense in the previous volume (regrettably in dilettante fashion) by Richard Wagner. The rising of musical nationalism, the development of rivalries especially that between Stravinsky and Schoenberg, the role of "peasant music vs. modern music" in the lives of Bartók, Kodaly, and Janáček, and the reaction of composers to the rise of totalitarian regimes in Italy, Germany, and the USSR are all issues that Taruskin tackles with great erudition and wit. As I've said about all other volumes in this series, this is not a book for those with no special musical training (as some volumes other Oxford History series are), however if you're a serious student of music there quite simply is nothing like this huge achievement.