5ths & double stops

Take just the root and the 5th of a chord, Do and Sol, and you have a 5th: a power chord in its smallest form. It's neither major nor minor, so it fits under almost anything. Playing two strings at once like this is called a double stop.

In position 1 the root and 5th of E, A and D are an open string plus the 2nd fret of the next string up. G and C put the root on the 3rd fret and borrow an open string a string further on.