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### GMC Forum _ THEORY _ Descending Perfect Intervals

#### Posted by: The Professor Mar 27 2013, 10:48 AM

What Are Descending Perfect Intervals?

In this Theory lesson we’ll be looking at one of the most commonly used intervals in modern music, the Descending Perfect Interval, which are related to the Ascending Perfect Intervals we looked at in a previous lesson.

To recognize and build Descending Perfect Intervals, you will need to have a decent understanding of their Ascending Perfect Interval cousins.

So, before you dig deeper into today’s theory lesson, check out the “http://www.guitarmasterclass.net/guitar_forum/index.php?showtopic=48244” lesson for a brush up on those intervals if needed.

If you’re ready to dive in, or have completed your review of Ascending Perfect Intervals, then here are the formulas for deriving and recognizing the two Descending Perfect Intervals.

Descending Perfect 4th Intervals

The first interval that we’ll look at in this lesson is the Descending Perfect 4th Interval. Here, you simply take an Ascending Perfect 5th Interval and lower the second note by an octave.

So, if you have the notes G-D, an ascending P5, and you lower the D by an octave you get the notes G moving down to D, a Descending Perfect 4th Interval.

Here are a couple of examples of Descending Perfect 4th intervals written out on different parts of the neck.

After you’ve learned how to build a Descending Perfect 4th interval, go ahead and write a number of them out and post your work below.

I will be happy to go over and check your work to make sure that you’re on the right track when it comes to identifying and writing this interval.

Descending Perfect 5th Intervals

The second interval we’ll look at is the Descending Perfect 5th Interval.

Here, you take an Ascending Perfect 4th, lower the 2nd note by an octave, and you get a Descending P5 Interval.

This means, that if you have the notes G-C, an Ascending P4, and you lower C by one octave, you get the notes G moving down to C, a Descending P5 Interval.

Here are a couple of examples of Descending Perfect 5th intervals written out on different parts of the neck.

After you’ve learned how to build a Descending Perfect 5th interval, go ahead and write a number of them out and post your work below.

I will be happy to go over and check your work to make sure that you’re on the right track when it comes to identifying and writing this interval.

#### Posted by: brwnhornet59 Mar 27 2013, 04:03 PM

Great stuff Matt...I take these ideas for granted naturally, without really looking at the learned methodology behind it (a descending -6th interval is an ascending major 3rd one octave lower etc...) because I have gone to such great lengths to learn them when coloring chords or improvising. Seeing it pointed out in this light is a great way of strengthening one's knowledge of any given interval from it's root whether ascending or descending...Very important stuff to have internalized IMHO...Knowing them in the myriad of shapes that the guitar provides is a daunting task and one I still work to overcome, but well worth the continued effort. Thanks!

#### Posted by: The Professor Mar 27 2013, 04:45 PM

QUOTE (brwnhornet59 @ Mar 27 2013, 03:03 PM)
Great stuff Matt...I take these ideas for granted naturally, without really looking at the learned methodology behind it (a descending -6th interval is an ascending major 3rd one octave lower etc...) because I have gone to such great lengths to learn them when coloring chords or improvising. Seeing it pointed out in this light is a great way of strengthening one's knowledge of any given interval from it's root whether ascending or descending...Very important stuff to have internalized IMHO...Knowing them in the myriad of shapes that the guitar provides is a daunting task and one I still work to overcome, but well worth the continued effort. Thanks!

No problem man, for sure. It may not come up on a daily basis but knowing how to recognize and write these intervals comes in handy from time to time. And always better to have them down and ready when you need them then get stuck in a bind!