Half Step Rules for Dominant Chords (In the key of G) Barry Harris D Dominant Scale - 5th mode of G major Same as D major, but with a flat-7. D7 Rule 1: Add a half step between 7 & 1 when starting on a chord tone. Rule 2: Add no half steps when starting on a non-chord tone. Worksheet prepared by Josh Walsh from Jazz-Library.com 2 Half Step Rules for Dominant Chords Rule 3: Add three half steps when starting on the 3rd, 5th or 7th. Between 7-1, 2-1 and 3-2. Rule 4: Add two half steps when starting on non-chord tones (2nd, 4th & 6th) Between 7-1 and 2-1. Credit for this magnificent system goes to the legendary educator, Barry Harris. This document is just my humble a empt to share a bit of what I learned from him.