I love the topic of resource books!
A few years ago I had the massive good fortune to spend an hour with Patrick Williams at his home. When I asked a similar question he said he would leave condensed orchestral scores around the house so whenever he sat how somewhere he could reach out, find a score, and learn.
The first book I ever bought on arranging was Dick Grove’s “Arranging Concepts”. It is a wonderful book. Dick was so methodical and organized in presenting material and logically walking students through scads of references, concepts, and real world examples. I still use his analysis technique of density and span of orchestration to double check my work and manage the emotional contours of pieces.
At Berklee the Earle Hagen “Scoring for Films” was the go to text. Don Wilkins, my instructor there, had studied privately with Earle.
Frank Mantooth was a friend and mentor. When I worked for the old Northwest Airlines I would use my flight privileges to fly from Minneapolis to Chicago once a month to have a lesson. Frank taught arranging from his “Jazz Voicings for Keyboards” book which focused on voicings in fourths, upper structure triads, and his own “miracle voicings”. While the book was geared to help pianists voice chords quickly I can still hear those concepts in his writing. He was a master theorist, great arranger, and a truly nice gentleman. I miss him daily.
Other books I’ve used and worn out include:
“The Contemporary Arranger” by Don Sebesky
“The Complete Arranger” by Sammy Nestico
“Instrumental Jazz Arranging” by Mike Tomaro
“Sounds and Scores” by Henry Mancini (I believe that’s the title … it’s in another studio at the moment)
I also use Nelson Riddle’s book often. I’m drawing a blank on the title. Excellent book with arranging examples and some marvelous stories from his experience.
Sorry for the windy post. As I said above, I love arranging books!