Hi All, Can you please help me to understand how Interval Inversion works? I’ve been studying music theory from talking bass.
I was struggling to catch how augmented and diminished switched together.
Is this useful to work my bass playing or should I get a deep dive on this?
I love inversion.
Basically, you are putting the bottom note to the top, while doing that it converts to the opposite. Major becomes minor, diminished becomes Augmented.
Whatever interval you are inverting would add up to 9, for example a Major 3rd inverted becomes minor 6th, if you inverted Major 7th then the inverted becomes minor 2nd, 4th to a 5th and so on. All add to 9.
It gets more fun when you started doing chords (triad) as it brings new sound and depth to the music. Have fun.
Let say on Augmented 5th inverted is a Diminished 4th
from Key of C.
C G > Perfect 5th then + 1 so G# (Augmented 5th) how do I invert that into Diminished 4th?
Hi @Samantha.Cooper !
The major scale intervals will help your bass playing.
Diminished and augmented intervals won’t help your bass playing.
It becomes a grammatical music theory game.
It has no practical purpose in any bass line you’ll play or song you’ll write.
Mostly because pop songs really don’t go in for this hardcore theory stuff.
Technically, if you want to see it all the way through, C up to G# is an augmented 5th.
(It sounds the same as a minor 6th, the only difference is in how it is looked at theoretically and spelled with letters.)
It will invert to a G# up to a C, which - if you want to be technically correct in naming this interval, is a diminished 4th.
It sounds like a major 3rd (Ab to C) because that’s what the sound is.
It has the different, much much much more rare and confusing name of diminished 4th only because of the rare and theoretical circumstances in the example.
Also the fastest way to get your butt kicked in the band, 
@Gio Sorry, but this was the part I’m confused about.
“It will invert to a G# up to a C, which - if you want to be technically correct in naming this interval, is a diminished 4th.
It sounds like a major 3rd (Ab to C) because that’s what the sound is.”
You meant to say Invert from C octave it comes to C B A G? I’m thinking I started counting from C octave to G (Perfect 4th)
since It was on Augmented 5th, should I go for it C, B, A, G# or Ab Backwards? how should I consider it diminished 4th? sorry I was confused to understand this.
Thank you for your help.
@Samantha.Cooper - here’s the explanation. Let me know if this attempt makes sense.
I’ll start with a visual, because I think that’s very helpful and necessary when dealing in music theory abstract stuff like this.
Intervals are always measure from whatever note is on the bottom. That’s why inverting an interval will change its name (and sound).
The initial interval of C up to G# has to be named as some kind of 5th because it moves from C(1st) [skips D(2nds), E(3rds), F(4ths)] and goes up to a G. Any interval from any kind of C to any kind of G has to be (according to the rules of music theory) written and named as some kid of 5th.
C to G natural would be a perfect 5th (since C to G in the C major scale is 7 half steps). If you raise the perfect intervals by a half step, they become augmented. So C to G# = augmented 5th.
When you invert an interval, the note on top becomes the note on the bottom.
So now you are measuring and naming the interval from G# up to C.
The interval will be some kind of 4th because:
G#(1sts) [skipping any kind - flat or sharp or whatever - of A(2nds), B(3rds)] up to C (4ths)
G# would go up 5 half steps to a perfect 4th at C#.
Because C natural is a half step lower than C#, the interval is no longer a perfect 4th. When you lower perfect intervals by a half step, they are called diminished intervals.
Thus G# to C would technically be called a diminished 4th.
Let me know if that makes sense now.
That was a great explanation!
For the OP, I think (in terms of learning how inversions work) that setting aside the augmented/diminished part here would help immensely. Unless of course you understand everything else already and that is the only remaining mystery.
Inverting the standard triad intervals alone teaches some important relationships and even sheds some light on why the circle of fifths and circle of fourths are the same, just in opposite directions.
Also a piano keyboard helps immensely when learning this.
@Gio It’s cleared now but one last thing. I’m trying to figure out if does the same if I divert from Diminished 4th to Augmented 5th? Is that same illustration what you did or there’s a difference ?
I am a little confused by your question. Are you asking that if you have a chord with a diminished 4th interval (i.e. a normal major third) and you invert it, is the resulting interval brween those two notes an augmented fifth? Then yes.
In Gio’s example, consider the major third (diminished fourth) dyad of G# and C. Inverted, that becomes C to G#, or the original augmented fifth he started with.
(Except there isn’t a C natural in the key of G#, that would be a B#, but lets just let that one go for now.)
Hi @howard, yes it is. I’m trying to rotate to Diminished 4th into Augmented 5th. Is that same procedure should I use to it?
from C to F (Perfect 4th) then E (Diminished 4th) what’s the procedure to know about its inversion of Augmented 5th?
I was using his method started from E, F, G, A, B until I reached C.
It’s 5 steps so I should it consider Augemented 5th as well?
Thank you for your patience guys, I really appreciate your effort to help me. I’m not sure if should I proceed to the next topic. while this topic not completely understand to me. yeah I do understand the concept 95%. however I don’t have idea how it works when I do play and how important it is. Someone said to me don’t make it complicated and just know the concept on the below.
• Major 3rd inverted is a Minor 6th
• Augmented 5th inverted is a Diminished 4th
• Diminished 5th inverted is a Augmented 4th
• Major 2nd inverted is a Minor 7th
• Major 6th inverted is a Minor 3rd
To reiterate my thoughts from before - these concepts are not important at all to your playing, and I have never, in my 2.5 decades of professional bass playing, have had to ever once think about, confront, or have to deal with - let alone invert - a diminished 4th.
It is strictly a theoretical and technical exercise that has nothing to do with practical bass playing at all.
The problem that you’re running into in your example is a very understandable problem and one that is stemming from your very astute common sense.
This intellectual excercise has nothing to do with common sense - it is only about strictly and dogmatically following theoretical rules, even when they make no practical or musical sense.
For example.
If you have a 4th of C up to F, that is a perfect 4th.
If you lower the F by a half step and want it to be a diminished 4th, you have to call it an F flat. Fb.
It is the same note as an E.
It is the same pitch as an E.
It has been given this theoretical name for no good reason other than it is theoretically possible to call it Fb.
C to Fb is a diminished 4th.
You will never see this in music you play.
No one will ever reference an E as an F flat. It won’t ever be in your life or your music.
If you spell the notes C and Fb, the correct interval description is a diminished 4th.
If you invert that, and start with an Fb, then the correct identification of the interval Fb up to C would be an augmented 5th.
These theoretical problems only exist as mental exercises.
As @howard said, learning the intervals and inversions that exist in the major scale, major and minor triads and the sounds and musical bits that you find in practical music examples makes sense.
I wouldn’t worry at all about inverting augmented and diminshed intervals, and have never brought this up to any of my students, even in the most advanced playing / learning circumstances because it is not relevant to bass playing.
I’m happy to keep going with this, because I do love abstract music theory and explaining it, but I want you to be fully aware that this information has no value to practical bass playing, and if it is a stumbling block, it can be absolutely ignored and you will live a rich and happy musical life.
Well, you really need to call it an F (of some flavor; here Fb) if it should be a fourth (of some flavor; here a diminished fourth). If it were an E (of some flavor) it would always be a third (of some flavor).
But, yes, it almost never shows up IRL… That said, this is what I came across just yesterday - but for the life of me, I can’t quite understand why it’s an Fb in this context… I actually think it’s wrong and then copy/pasted wrong… 
@markjsmith, would you weigh in on this?
So what you’re saying is:
Turn up early
Help load the gear
Learn the songs
Don’t be a dick
Got it 
This is 100% incorrectly transcribed.
The major 7th of the F major 7th chord that is being notated there should be written as an E.
Fbs certainly exist in the wild, but not in the places most people go.
You have to go deep, deep into the jungles of weird music to come up with some legitimate Fbs and Cbs and E#s and B#s.
Jazzers will avoid them at all costs.
Classical folks will use them (and double flats and double sharps) because of theory.
This transcription must have come from a horn transcription in a different key, and the person who put it into bass clef didn’t check it or correct it.
The Gbs from A natural are also bad transcriptions. F# would be a better read.
Yeah I had to laugh when thinking of G# as a key above. If it were a thing (as opposed to just using Ab), it would contain a B#, E#, and F##.
Here’s a tangent on inversion that’s interesting 
It’s all clear now. I’m so thankful to you guys that I can share my challenges and doubts while studying Music Theory. You only guys provide answers actively with patience in this forum.
I just scrolled straight through all the posts looking for you saying this 
