Heinrich Schenker, John Rothgeb, Jurgen Thym - Counterpoint

Counterpoint (Kontrapunkt in the original German) is the second volume of Heinrich Schenker's New Musical Theories and Fantasies (the first is Harmony and the third is Free Composition). It is divided into two "Books", the first published in 1910, and the second in 1922.
The subject matter of the work is species counterpoint, also referred to as "strict counterpoint". Book I is concerned with the construction of the cantus firmus and the rules of counterpoint in two voices; Book II treats the cases of three- and four-voice counterpoint. Schenker thus follows the model of Fux in presenting all of the species in turn before adding additional voices.