The Music Theory Advantage TM
Rapid Skill Development with the Cycle of Thirds

Created by
Max Maxwell
All Rights Reserved.

Introduction (Home)     Course Index     How to Practice
Answer Charts     Projects in Development

<<=PREV  How to Find Perfect 5ths  NEXT=>>

You now know how to find Perfect Primes, 2nds and 3rds above or below any note. We will learn how to find Perfect 4ths after learning how to find a Perfect 5th above or below any note. After you learn 5ths, you will learn how to find 4ths via the principle of interval inversion.

A Perfect 5th is an interval that contains seven half steps.

The Perfect Fifth Above A is E

You already know that in the Cycle of Thirds, a 3rd above a note is forward in the cycle. A 3rd below a note is backward in the cycle. Perfect 5ths work in the same way. A Perfect 5th above a note is two steps forward in the cycle. A 5th below a note is two steps backward in the cycle. Regarding the illustration above, you know that E is two steps forward in the Cycle of Thirds above A (A-C-E). To find a Perfect 5th above any note, just count two steps forward in the Cycle of Thirds. There are no Major or minor 5ths. Remember to match the signs if starting with a note that is sharp, flat, double sharp or flat. Example: If a perfect 5th above A is E, then a perfect 5th above Abb is Ebb. Finding 5ths is one example of why it is very important that you master reciting the Cycle of Thirds. If you are still struggling to simply recite the Cycle of Thirds, then you must stop now and go back to master the first three steps in this course.

A Perfect 5th above G is two steps forward from G: 1) B, 2) D.
D is a Perfect 5th above G.

A Perfect 5th above C# is two steps forward from C#: 1) E#, 2) G#.
G
# is a Perfect 5th above C#.

To find a Perfect 5th below a note, count two steps backwards in the Cycle of Thirds.

A Perfect 5th below E is two steps backward from E: 1) C, 2) A.
A is a Perfect 5th below E.

A Perfect 5th below Dbb is two steps backward from Dbb: 1) Bbb, 2) Gbb.
G
bb is a Perfect 5th below Dbb.

One BeautiFul exception

With the method for finding fifths above or below a given note, the cycle gives you the correct answer by counting two steps forwards or backwards. There is one exception. When moving two steps forward from B to F, you have to add one half step by raising the answer one half step (B to F#). This is also true from B# to F# (B# to F##) and Bb to Fb (Bb to F).

This also means that if you started from F and counted backwards two places to B, you must add one have step by lowering the answer one half step to Bb. This also applies to F# (F# to B) and Fb (Fb to Bbb). This exception exists because the distance between each two steps in the Cycle of Thirds is a perfect 5th with seven half steps, except the fifth from B to F (six half steps), which is one half step short of a Perfect 5th.

Below is a chart demonstrating how moving from any form of B to F raises F by one half step and moving from any form of F to B lowers B by one half step.

From B to F          From F to B

Raise 1/2 Step             Lower 1/2 Step

 B# to F## B to F# Bb to F Bbb to Fb F## to B#      F# to B      F to Bb      Fb to Bbb

An Easy Way to Remember:

In order to easily remember this exception, I give you the following visualization. Whenever you think of moving from B to F or from F to B when finding 5ths, imagine a bunny (B) looking up to a fly (F - which is up in the air) and the fly (F) looks down at the bunny (B).

The bunny (B) always looks up to the fly (raises F). The fly (F) always looks down at the bunny (lowers B).

A Perfect 5th above B is found by counting forward two steps. From B that is 1) D, 2) F. Remember the bunny looks up to the fly so you must raise F one half step to F#.  F# is a Perfect 5th above B.

A Perfect 5th below F is found by counting backward two steps. From F that is 1) D, 2) B. Remember the fly looks down to the bunny so you must lower B by one half step to Bb. Bb is a Perfect 5th below F.

Exercise:

Each question asks you to find a Perfect 5th either above some form of B or below some form of F. In the blanks, fill in the proper form of B or F. If some form of F is the given note, then count backward two steps in the Cycle of Thirds from F to B and put in the correct form of B.  If some form of B is the given note, then count forward two steps in the Cycle of Thirds from B to F and put in the correct form of F. This exercise is for practicing lowering (B) and raising (F) by one half step when determining the perfect fifth between them. Cover up the BF lists above.

1. B  _______         2. F##  _______       3. Bb  _______        4. F#  _______

5. Bbb  _______       6. F  _______         7. B#  _______        8. Fb  _______

Exercise:

Name the note that is a Perfect 5th above the given note. Remember to count two steps forward in the Cycle of Thirds. Also, remember moving from any form of B to F raises that form of F by one half step.  Use the interval charts on the answer charts page to check your answers.

 1. A  _________ 2. Eb  _________ 3. B  _________ 4. F  _________ 5. C#  _________ 6. Db  _________ 7. Gb _________ 8. A#  _________ 9. E  _________ 10. Bb  _________ 11. F#  _________ 12. C  _________ 13. G  _________ 14. D#  _________ 15. Ab  _________ 16. E#  _________ 17. B#  _________ 18. Fb  _________ 19. Cb  _________ 20. G#  _________

Exercise:

Fill in the blanks with the note that is a Perfect 5th below the given note. Remember to count two steps backward in the Cycle of Thirds. Also, remember moving from any form of F to B lowers that form of B by one half step. Use the interval charts on the answer charts page to check your answers.

 1.  _________ A 2.  _________ Eb 3.  _________ B 4.  _________ F 5.  _________ C# 6.  _________ D 7. _________ Gb 8.  _________ A# 9.  _________ E 10.  _________ Bb 11.  _________ F# 12.  _________ C 13.  _________ G 14.  _________ D# 15.  _________ Ab 16.  _________ E# 17.  _________ B# 18.  _________ Fb 19.  _________ Cb 20.  _________ G#

Copyright © 2008-2011 Kenneth J. Maxwell Jr.