You can think of guitar chords as pairs of two notes that have been arranged to sound the same. The first note is either the root note or the 3rd or 5th, depending on whether you are playing in the major or minor keys. There are a lot of possible chords and they can be confusing especially if you’re not used to thinking about chords in the same way. You might be thinking of them like a bunch of scales mixed together to form one chord, but this isn’t necessarily true.
There are a few chords that are commonly called single notes. These are the first note on the string, the note that is closest to the chord note. In a major scale, the root note of the chord is C. But in a minor scale, or even a minor pentatonic, the root note is F. These are called chromatic and they can be played either with the left index finger or the right index finger to make one big chord.
This picture shows how a common guitar chord shapes up
You can think of a chord as making a melodic melody, but sometimes we also use it to make a melodic sub-melody to fit into other chords. You might be thinking that a chord is a note with a tone, but that’s not necessarily true either. Some chords are a perfect fifth apart from the rest of the chord, but they are just a single note, but other chords are the entire note, a chord note.
The first note of a chord isn’t always in the chord. In other words, you don’t always have to think about which note is the first note in a chord. There are a few exceptions. The notes which are common chords are Dm, Em, Gm and Fm. Then there are a few chord shapes that are called triads, for example, A7, B7, Dm7, Em7. These are just the notes of a basic chord, but they are sometimes called “root” or “third” notes. You can see which chord note the first note is by making this symbol:
And it is the shape that plays the first part of a chord, but you can easily find the root note or the 3rd or 5th.
Other commonly used notes are C# and Ab, and then you find these chord shapes as A7, B7, Cm7 and E7 (also see C7, which plays a 5th and the C major scale shape).