Basic Guitar Theory 1: I IV V Songs in the Key of G

It is best to start with the simple.
The most important chord of a song is the key.
The root note is the most important note of a chord.
This lesson is about 3 chord songs where the root chord is G, the same as saying the key of G.
The root chord is G because the most imporant note of the chord is a G note.
G is the I chord, where in a I IV V song, G is a major chord.
I IV and V describe the 3 chords in the song; a G, chord, a C chord, and a D chord.
Each chord of a I IV V song is major.
What makes this chord a G chord is that it has the 3 different notes: G, B and D.
This is a G chord:
	Open	1st fret	2nd fret	3rd fret
thinnest string				G
	B
	G
	D
			B
thickest string				G
This is how to fret this G chord.
Fretting a chord is the same as saying how to use your fingers to play it.
	Open	1st fret	2nd fret	3rd fret
thinnest string				pinky finger
	no finger
	no finger
	no finger
			index finger
thickest string				middle finger
Here is another G chord that I find easier to play.
It doesn't sound very different.
I recommend choosing which of these two G chords based upon which one you find easire to play.
	Open	1st fret	2nd fret	3rd fret
thinnest string				pinky finger
				ring finger
	no finger
	no finger
			index finger
thickest string				middle finger
Again, it has the same three not G, B, and D, because it is a G chord.
	Open	1st fret	2nd fret	3rd fret
thinnest string				G
				D
	G
	D
			B
thickest string				G
The next chord is the IV chord. It is an C chord. It is a C chord because it has the notes C, E, and G.
	Open	1st fret	2nd fret	3rd fret
thinnest string	E
		C
	G
			E
				C
thickest string
This is how to fret a C chord.
	Open	1st fret	2nd fret	3rd fret
thinnest string	open
		index
	open
			middle
				ring
thickest string
There are other ways to play a C chord.
This one is useful if you don't have a mic and are playing a very small venue.
It adds a G, as a bass note. Some like it because by using 6 strings it is louder.
It is really a G/C chord, which is really just a fancy way of saying that the bass is a G and not a C.
	Open	1st fret	2nd fret	3rd fret
thinnest string	E
		C
	G
			E
				C
thickest string				G
	Open	1st fret	2nd fret	3rd fret
thinnest string	open
		index
	open
			middle
				ring
thickest string				pinky
The last chord of a I IV V chord series in the key of G is a D chord.
It is a D chord because it has the notes D, A, and G flat.
	Open	1st fret	2nd fret	3rd fret
thinnest string			G flat
				D
			A
	D
thickest string
	Open	1st fret	2nd fret	3rd fret
thinnest string			middle
				ring
			index
	open
thickest string
There are other ways to play a D chord.
This one is useful if you don't have a mic and are playing a very small venue.
It adds an A, as a bass note. Some like it because by using 5 strings it is louder.
It is really a A/D chord, which is really just a fancy way of saying that the bass is a A and not an D.
	Open	1st fret	2nd fret	3rd fret
thinnest string			G flat
				D
			A
	D
	A
thickest string
	Open	1st fret	2nd fret	3rd fret
thinnest string			middle
				ring
			index
	open
	open
thickest string