Guitar Chords Info
Chord names are the same for all instruments, so although this is for guitar players, all the same information will work on piano/keyboard. There are two components - the alphabetical name, and numbers.
The alphabetical names cover all 12 notes, by adding sharp and flat signs (♯ or♭)
The note names go A B C D E F G. If you add in the sharp and flat signs it covers the other notes.
The numbers tell you the interval from the root note of the chord, so by counting through the major scale from the root note, you can work out what the added note should be. This seems complicated, but in practice you can just memorize the shape and it's a lot easier. Let's take C6 as an easy example: the basic chord is C major, and you add the sixth note of the C scale
C D E F G A - so C6 is a C chord with an A note added.
Play this chord and it will sound like The Beatles song Fool On the Hill.
You may find some of my other hubs such as Guitar Chords 101 and Guitar Chords 101 Part 2 will be helpful in understanding chords on guitar.
Guitar Chords, group pictures
A chord variants
Look at the top line - if you play these chords in sequence ( the loop means a half barre where you flatten your first finger) the top note is coming down one fret or one semitone at a time.
When G sharp is the top note, the chord is called A major 7th
When G is the top note, it's A7
When F sharp is the top note, it's A6
On the last line is another way of doing the same thing, only here it's the central note that moves down.
G chord variants
On the second line I've shown the same concept applied to a G chord.
When the top note is F sharp , you have a G major 7 chord
When the top note is an F, you have a G7 chord
When the top note is an open E, it's a G6 chord.
Although it's shown that way here, in practice the moving note could be in the middle of the chord somewhere too - and will often sound better that way.
From D the middle note goes down to form D maj7 and then D7, finally D6.
C Chord variants
Starting with a C chord - just lift your first finger to form a C maj7 chord, with an open b string. The notes of the chord are C E G B, or 1 3 5 7 in intervals. As you can't go down any further on the second string, C7 has the added note on string 3, and so does C6.
This chord progression is used in some great songs, such as Something by The Beatles and Simple Twist of Fate by Bob Dylan.
Am and E7
The Am and E examples show you that you can use the same shape moved over one string to form many different chords - this reduces the amount of information you have to remember, so it's a useful trick to learn.
Intervals and theory
If you play piano or keyboard, try playing these chords as it will really help you with the theory side of music. The intervals of any chord can be described in terms of intervals, the distance up the scale from the starting note. The advantage of this approach is that you can transfer the information more easily between chords.
Major chord intervals: 1, 3, 5
Major 7th: 1, 3, 5, 7
7th: 1, 3, 5, b7
6th: 1, 3, 5, 6
Minor: 1, b3, 5
I would also encourage experimentation. Just see what happens when you move a note within a chord shape, or add open strings to the mix.