by DanK ?? Fri Jan 27, 2006 12:28 pm The Intervalic descending thirds or whatever means that in the A mixolydian scale, you are descending in intervals of a thirds. i do the exact same trick going up the scale too. ok so the tenth fret on the high e string is a B note. the relative minor is a B note, on the seventh fret. that is a minor third, descending. the next third is between the C# on the 9t