If I did have the ability to write music though, I'd definitely look at "The Music Master Ensemble Book" by Graham Bennett, part of the "Music Master" series. A technical look at creating multi-part pieces of music, it's a workbook perfect for a senior composition class at any college.

While other volumes in the "Music Master" series focused on techniques for individual composition, the "Ensemble Book" shows how different instruments work together. The book follows a natural progression of music writing, beginning with the electric keyboard and moving onto string quartets, choral arrangements and jazz band ensembles. Composers get a multi-step pattern for arranging songs and examples to compare their work against.

The construction of the book offers room for composer trial and error, with exercises and bare music staffs provided liberally. These range from simply translating between key signatures and clefs to the more complicated options of extending melodies and transposing ranges. Designing a quartet takes you through each movement individually, showing how the first creates the second and so forth. And at the end of each chapter, there are crossword puzzles or other word games to provide a vocabulary and history background in a less formal setting.

"Ensemble Book" is certainly a useful manual, but it's definitely not intended for novices. It seems to assume that you have at least a passing knowledge of how to write music, and offers little in the way of how it sounds - mostly tools and historical background to aid in construction. The descriptions of how to construct a song are more technical than they are melodic, and there's no CD or other audio tools to help a reader along.