Double stops are a nice technique to add to your lead guitar repertoire. They’re pretty simple – where you play two notes/strings together. Another name for them is dyads – two notes played simultaneously, whereas chords are 3 or more notes played at the same time.
This lesson will show you some double stop fingerings and exercises to get your fingers used to the physical application of playing two notes at the same time.
There’s no hard and fast rule about when double stops should be used. They are simply used to complement standard, single string lead phrases to add a bit of colour and variation to solos and rhythm playing.
However, just as much of your standard phrases will draw notes from a given scale, so too must your double stops reside within a scale and/or key to ensure the notes don’t clash with the backing music (unless, of course, you want them to clash!).
Read more and for great exercises at http://www.fretjam.com/guitar-double-stops.html