Hi Lee. Hope all is well. Ok, My question is when practicing Dim7 chords when I move them up to a new root ie- Cm to Em , would the next movement be to Gbm then to Am? If so ,Then I understand what minor 3rds mean. But although the shape stays the same does the new root note need to be on the same string as the first chords root note? I know the correct chord formula (1,3b,5b,7bb) so my question is purely about the movement and the root notes position. I’m afraid to try and figure this out alone and possibly waste time with incorrect thinking. Thanks in advance, Sean
Hi Sean. Not sure if I’m completely understanding your question so I’ll just try to give some detail, hopefully it will cover your question.
The dim 7 chord is created by stacking intervals a minor third apart. On one string, a minor third is equal to three frets apart. On the B string 1st fret we have the note C: move three frets up and we land on the 4th fret (Eb): three frets up again and we’re on the 7th fret (Gb): three more and we’re at the 10th fret (A).
Now if we go up another three frets we’ll end up back on the C, 13th fret. This makes it fully symmetrical. It’s for this reason that any note in the dim7 chord can be considered the root. If we move a dim7 chord then each note will move relatively, if we move the chord up three frets then each note moves three frets accordingly. The result is the same chord but with a different inversion (note order in pitch).
Generally speaking, we put chord roots in the bass, the lower pitched note usually stands out more. This isn’t any kind of rule, it’s just what we do, usually. Think of a typical C major chord like this..
E: 0
B: 1
G: 0
D: 2
A: 3
E: x
The note on the A string is C, it’s the lowest note in the chord. If we now add the G on the 6th string 3rd fret then we end up with C/G (c over g).
E: 0
B: 1
G: 0
D: 2
A: 3
E: 3
Whether we call it C/G or not, it’s still just a C major chord. Some people play it that way as normal. If we mute the two low strings in the same chord then the lowest note will become E (on the D string). We could now call this chord C/E if we wanted to be clear about how it’s played – or if it was of no importance to the song then we’d probably still just call it C major. We could play a C major chord in various places on the neck, all that changes is the note order but this never changes the chord’s name.
Back to diminished 7. Using the same “rule” as above, this means that we cannot define a diminished 7 chord as a single key type because of each chord note being the same interval apart. Therefore Cdim7, Ebdim7, Gbdim7 and Adim7 are all the same chord. Let’s say we start a the chord on the A string, third fret – we’ll call it Cdim7. If we now move this along to the 4th fret we’ll just call it an Ebdim7 because the Eb is the lowest note in pitch. If we wanted we could call it a Cdim7/Eb but this would be pointless, unless maybe we wanted to be specific that the C needs to be in the bass. Most of the time however, we’d see “Cdim7” and just assume the C should be in the bass, otherwise it would have been named Ebdim7.
The bottom line is the only thing that can really define this chord is the inversion, what’s in the bass, and in many cases it doesn’t even matter what inversion we use if all we’re doing is playing chords in a backing situation.
Not sure if I’ve answered your question at all here 🙂
Feel free to come back and ask more if not.
