Counterpoint texts tend to resemble one another in the underlying principles of voice-leading they espouse and in the kinds of orderings of rules they provide, but no one could accuse the harmony texts of, let us say, Heinrich Schenker and Hugo Riemann, or of Allen Irvine McHose and Walter Piston—or for that matter, of Arnold Schoenberg, Paul Hindemith, and Roger Sessions—of being mutually compatible, either in premise or in practice.

Harold Powers, "Is Mode Real", p.18,10.