Q: I just got your book and I believe it´s an interesting approach. I just have one question: What about modal or minor scales? The harmonic minor maybe close to his major relative, but will the notes have the same feel? Will the G sound the same on A minor or C major? And how will I peceive the G# in C major and melodic A minor?
A: All notes, no matter what the key center type, will have the same sound. Therefore. a G in the key of C major, C minor, C mixolydian etc. will all sound like the 5th of the key. The note G does not sound the same in A minor as it does it C major. In the key of A minor a G will sound like the b7. In the key of C it will sound like the 5th. You will hear a G# in the key of C as the #5 and in the key of A minor a G# will sound like the 7th.
For more information you might check out the 25 Ear Training Tips to understand the process better.