Another funky extension to spice up your blues is the 13th. It is often combined with the 9th as they work in concert to create a very “cool” sound. As such, the 13th chord is frequently used in a funkier blues style. We can make our rhythm 16th-note based to increase the funkiness of our blues progression. When strumming 16th-notes, the forearm must be in continuous rotation, with the arm traveling downwards on each eighth-note.