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.

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.

In my other hub (Guitar lesson 2) root 5 chords are covered so it will help if you check that out too.

The loop symbol tells you to play a Barre chord - if in doubt, check my hub Guitar Barre Chords.

All this information is relevant to piano/keyboard too, and you might find it a quicker way of understanding theory on piano.

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

becomes

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.

When you've got the idea, you can use easier chords to replace the barre chords.

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 accomodate 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!)