The Orchestra by Paul Bekker

A superb, short treatise on the history of the orchestra, from its 17-century origins all the way up to Schoenberg and Stravinsky. The real value here is in understanding the context in which the orchestra developed. Bekker is strictly old-school, but his information is excellent and his view on the modern direction of orchestration quite generous and informed. A very quick, fun read that improves your understanding of what you’re hearing immediately.