Question: I am learning to play guitar by myself, and it is hard to understand some theory about how guitar chords are built. For example let's look at a G chord. I have found two of the most simple definitions:

[![G chord](https://i.stack.imgur.com/zP4WA.png)](https://i.stack.imgur.com/zP4WA.png)

If we write down corresponding notes for both of them we will get:

* **G B D G** for the former
* **G B G** for the latter

But as I understand major chords are built from 1st, 3rd and 5th notes of the major scale, which is:

**G A B C D E F# C**

Therefore it should be **G B D**. Where am I wrong?

The same question is about E chord.

[![E chord](https://i.stack.imgur.com/FyV4T.gif)](https://i.stack.imgur.com/FyV4T.gif)

Notes are: **E B G** whereas according to the scale **E F# G# A B C# D# E** it should be **E G# B**.

And one more question. How is it possible for chord to have more than 3 notes, like the G chord on the 3rd fret, if the chord is a triad?

Answer: 
> 
> How is it possible for chord to have more than 3 notes, like for G chord on 3rd fret, if chord is a triad?
> 
> 
> 

A chord with three scale degrees doesn't have to only have three notes - it can contain repetitions of those notes in different octaves.

> 
> [![G chord](https://i.stack.imgur.com/zP4WA.png)](https://i.stack.imgur.com/zP4WA.png)
> 
> 
> If we write down corresponding notes for both of them we will get:
> 
> 
> * **G B D G** for the former
> * **G B G** for the latter
> 
> 
> 

In both of these diagrams, you can play *all* the strings - not just the ones you put your fingers on! So actually you have 

* **G B D G D G** for the former
* **G B D G B G** for the latter

So, you see that these chords *are* made up of the notes G, B, D - it's just that some of them are repeated.

So, how do you know when you can play the open strings (the ones without your finger on?

[![enter image description here](https://i.stack.imgur.com/8yTgF.png)](https://i.stack.imgur.com/8yTgF.png)

Take a look at this picture. The G string (that you *should* play) has a **O** symbol, which means you should play the string. But the E strings have an **X** symbol, meaning that you shouldn't.
While there is the triad, there is all the other notes in the scale that you can add to change how chord sounds. Such as a dominant 7 on top of the triad to make the chord sound bluesy. Or a maj7 which makes the chord sound jazzy. Those are just the start to add on notes but is another way a chord could have more than just the basic triad. Learning more about the add ons and experimenting with them in progressions and such can really spice up your playing. Also it actually helps a lot with soloing on chords.