Guitar chord theory
Chords in E
Every now and then when you're learning to play the guitar, you make a real breakthrough and it all gets easier and starts to make sense. For me, understanding the concept of harmonised scales was one of those really important discoveries.
If you build a chord on every note of an E major scale, using only the notes from that scale, you get this set of chords. It's incredibly useful, as most pop and rock songs will use this set of chords, called the harmonised scale,and it's also a starting point for songwriting. It should mean that learning all guitar songs gets much easier and faster too.
These are root 6 chords, where the root note is on string 6 (low E) Chords 1, 4, 5 are major. Chords 2, 3, 6 are minor - same pattern for all the different keys.
Although the chords here are going up the neck, and following the notes of the major scale, they don't have to be played this way - you could just play some of them as first position chords. It does help, however, as you can see the distances between the chords, which retain the same pattern for all the different keys.
In my other hub (Guitar lesson 2) root 5 chords are covered so it will help if you check that out too. The root 5 chords would be - for the key of A -
G♯m7b5. - then A again
Notice that the pattern of chords is the same for all the different keys - the most common keys are shown in the table below. Tip - learn the 1, 4, 5 ( I IV V ) chords first, they are the primary chords you will find in every song, the 5 is usually a dominant 7th chord, leading back to chord 1 or the tonic.
The loop symbol tells you to play a Barre chord - if in doubt, check my hub Guitar Barre Chords. If you struggle with these chords, and most people do, there are some short cuts here.
All this information is relevant to piano/keyboard too, and you might find it a quicker way of understanding theory on piano.
When you really have this down, try lifting the barre finger so strings 1 and 2 are open, but keep the string 3 note the same as it was in the barre chord. These are great sounding chords, covered in my other hub Guitar - the best chords.
Guitar chords and harmonised scales
This chart can help with transposing, or changing key. For instance, if you're singing a song in C and it's too low for your voice, try moving all the chords to D.
C, Am, F, G
D Bm G A
This is also known as a I vi IV V progression.
To play the chords in G, just move the pattern for E up 3 frets.
NB - the distance between the chords and the type of chord used are the same, only the pitch has changed.
When you've got the idea, you can use easier chords to replace the barre chords.
More on transposing
Transposing is frankly a real pain. Due to the inordinately messy way music theory has evolved you have lots of different instruments struggling to communicate with each other, and typically you will need to accommodate transposing instruments such as the saxophone, which comes in Eb and Bb varieties, and especially singers, who all like different keys.
A capo is your friend here - you can play in D with the capo on fret 1, and everything will come out in the key of Eb. It can really help, but also try to understand how to use the info above to change key.
For keyboard players, all you have to do is hit the transpose button (but then remember to take it off again if you're halfway through a concert!)