# Music theory. Extended Chords and barre chords

The Cadd9 chord is played on the 3rd,2nd and 3rd fret of the A D and B string respectively.

What would be the resulting chord if I were to barre the first fret with my index finger?

Or for that matter, what would happen to any open chords that operate from fret 'n' and I barre fret 'n-1' where n is not equal to 1.

Is there any way of finding what resulting chords I get when I barre open chords that operate from the second fret onwards(like Dsus4,C5, etc) ?

And by "way of finding" I mean, how we determine that a Gmaj chord is just moving the Fmaj chord by a wholestep because F and G are one tone apart.

• It's actually played with the 3rd and top strings (open) as well. Giving C, E, G, D, E. And other options include bottom open or bottom 3rd fret, and top 3rd fret. Or possibly a combination!
– Tim
Commented Dec 6, 2018 at 18:13

```X 3 2 0 3 0
X C E G D E
```

re-arrange the letters by thirds...

`C E G (no B) D`

That give us `Cadd9`, no minor seventh so it's just an `add9`.

That chord is open so we can sort of think of it as barred at fret zero.

Next, barre the first fret and you get...

```X 3 2 1  3 1
X C E G# D F
```

re-arrange the letters in thirds...

`C E G# (no B) D F`

That gives us `C#5add9add11` or maybe it should be `C11#5add9`. I would not spend time trying to give it a sensible label, because the barre was just arbitrarily added. That's not how functional chords are constructed. Is this really a 9th or 11th chord? Where is the dominant 7th then? Without the 7th we have to resort to using `add` labels. But do you really mean to construct a chord based on the ^1,^2,^3,^4 scale degrees then a #^5? This is more like non-tertial harmony or tone-clusters. You can do it if you want, but trying to figure out a label for the result doesn't make much sense. I don't mean to sound chiding, I just want to 'unpack' what's going on in the example.

Maybe if this chord was followed by sliding all the non-barre fingers up one fret the "chord" could be considered a type of suspension/retardation between a `Cadd9` and a `Dbadd9`. If so, formally it should not be called a chord.

But I'm not sure I you meant to switch fingers 2,1,3 to 3,2,4 and move them up one fret to match the change of the barre from open (fret zero if you will) to fret 1. Personally, my hand can't make the stretch to do that, but it would be...

```X 4  3 1  4  1
X Db F Ab Eb F
```

Notice I made the enharmonic change of `G#` to `Ab`.

Re-arrange the letters in thirds...

`Db F Ab (no C) Eb`

That gives us `Dbadd9`

Notice that I came up with a `Db` root whereas @Tim came up with a `C#` root. Neither choice is right or wrong. Certainly guitar seems to "favor" keys with sharps so `C#` is a natural choice.

I chose `Db` because of the change of the `E`. If we sharp the `C` then we should sharp the `E` and get `E#`. Personally I think it's easier to read `F` natural. So I started by changing the pitch class - meaning the letters. So, `E` goes up to `F` and `C` goes up to a `D` that is a half step above which is `Db`. My root is `Db`.

Sorry if that's a bit long winded! But I thought it might be helpful to explain. When you get used to making enharmonic changes you kind of do all that stuff without much thinking.

But the important point is theoretically you could take any open chord shift the fingered tones up X frets and then barre at fret X to get a chord of the same quality but with the root shifted by X semi-tones. Some of the resulting chords may be impossible or difficult to play especially the ones based on open `C`, `G`, and `D`.

• I think we're both on a hiding for nothing with this one!
– Tim
Commented Dec 6, 2018 at 22:21
• I like your answer very much, but I would change your first example from 032030 to X32030 because the first string is not played. (Consequently the second example would be X32131) Commented Dec 7, 2018 at 16:48
• @coconochao, good point. I missed the X in the chord diagram. I updated my answer. Commented Dec 7, 2018 at 17:00

You need to identify all the played notes, then try to form a major or minor triad from them, if you can, initially.

Your idea gives, bottom to top, F, C, E, G#/Ab, D and another F. Nothing there gives a triad as in 1 3 and 5. C&E is part of Cmaj., E&G# part of Emaj., D&F part of Dm., but nothing decisive. A name could be offered for it, but it's going to be contrived, and not a lot of use to many, if any, and I'd be hard pushed to find a useful place for it in a song.

Your last paragraph muddies things, as there, you mention wholesale moving of a complete shape, which is not what you describe earlier. If indeed that is what you meant, then moving Cadd9 up by a fret, and barre the 1st fret, then it's simply C#add9.

Enlightened by your comment, it's quite complicated, as with each shape, different strings will change notes when a barre is applied. Creating different notes in relation to the original chord/shape.

• The last paragraph was an example to show how one determines chords when complete shapes move up and down the fretboard. I wanted to know if there was any hard and fast rule (like the example I mentioned) for determining chords that are obtained by barring the previous fret. Sorry if I caused any confusion :) Commented Dec 6, 2018 at 18:12
• What happens to other chords like D5 when they are barred on the first fret? Commented Dec 6, 2018 at 18:17
• It's going to depend on what notes get changed. I can think of a couple of 'D5' shapes, but the solution is simple. Write out the individual notes, and try to find a chord they constitute. There's no simple answer here, apart from that. As there are too many different shapes to consider.
– Tim
Commented Dec 6, 2018 at 18:21