The Blues Pattern (Scale)
G
Position 
Position 
Position 

  This is the pattern you can use to accompany the Blues in G.  The root note is G, and the   
   other G notes are coloured red.  The "blue" notes are coloured blue, and the rest of the notes   
  in the pattern are black.  If you know the key is G, just play these notes.  If the key is A,  
  move everything up 2 frets.  Any key can be played just by sliding this pattern up and down  
  the neck.  If you don't know the key of a piece you are hearing, slide your finger up and down 
  the low or high E strings (1 and 6 strings) until you can match the note to the tune.  
  Experiment with Position 1 until you are somewhat comfortable with it.  Then move on to the 
  other positions.  Above all, have fun!
Position 
Position 
G
G
G
Links to backing tracks in the Key of G

Link 1

Link 2

Link 3