How to Use This Book Most Efficiently
I believe the big challenge in a music theory/harmony book is getting the information off the printed page and into your head, and also into the muscle memory of your fingers or embouchure (or both). Much of the material here is provided in a workbook format along with training exercises that will help you participate more deeply in the learning process.
If you are planning on becoming a music arranger or will be documenting your music extensively on paper (or electronically) I recommend that you complete all the workbook assignments thoroughly, writing chords and scales in all keys. If you are primarily interested in performing music you can skimp on some of the pencil-in chores as long as you can play and understand the material in all keys on your instrument. Strive to hear the music in your head.
I generally recommend that you work your way through the theory part of this book in the order that it is presented because earlier information is a building block for information that comes later. However, I recommend that you begin practicing the Jumpstarters concurrently with the theory section, as soon as you are able to.
The Jumpstarters are presented in a general order of difficulty and complexity but you can practice them in any order. Single note instruments can just play the top stave. Feel free to make changes to the melodies and chord voicings to make them easier to play on your instrument. You may likely need to change the octaves or limit the range of the exercises, plus possibly make adjustments for easier fingerings. Do not kill yourself on anything that seems too hard – either adjust it to make it easier or simply move on to another exercise. Remember – these are just ideas, not formal compositions – you can change them to make them work better for you.
Play each key area as many times as you like to get comfortable before trying to play Jumpstarters as written.