The term double stop refers to two notes being played (stopped) at the same time. The intervals most commonly used are thirds, fourths, fifths, and sixths.
Let’s begin by harmonizing the major scale in thirds:
Now let’s harmonize in fourths:
Now let’s harmonize in fifths:
And last, we’ll harmonize in sixths:
With these intervals, you can create some very interesting solos. As we all know, however, anything used in excess can become boring. So what I like to do is develop licks that incorporate various different intervals. The first two examples are ascending licks (in the key of D) made up of thirds and fourths.
Next is a descending lick in A, made up of major- and minor-third intervals (and also one major-second interval):
A lot of my licks incorporate one or more single notes along with double-stop notes. This first one is in the key of A:
Here’s one in G:
Here are some licks that incorporate bends with double-stop licks: