Crediting his readers with a familiarity with musical theory, Fenby makes sporadic attempts to explain some abstractions to the non-musician -- as if he suddenly realized that the series was aimed at a general teenaged readership. (Like the titles by Harding and others, below, this follows the series format in being under 100 pages and liberally illustrated with photographs, sketches, and excerpts from musical scores -- mostly arranged for piano. Covers for the new titles substitute colorful, semiabstract paintings for photos of the composers.) Fenby's position as amanuensis to the composer in his last blind, paralyzed, syphilitic years gave him an inside view of Delius as a man and musician, and descriptions of Delius at that time when the author knew and worked with him are especially interesting. In earlier parts, however, Fenby sometimes falls prey to pedanticism, his attempts at turning prose into poetry fare poorly, and he fails to explain what makes music ""Delian.