Up until now, the left hand has only been playing the root note of the chord. The following two 12 Bar Blues in the keys of C and G respectively use a Blues riff in the left hand. Practice the left and right hand parts separately, before combining them. Experiment with your own left hand riffs and right hand chord voicings and rhythms to make up your own 12 Bar Blues songs.
In the following 12 Bar Blues in C, you will notice that the first three notes of the riff are the first three notes of the chord in each bar. The first note of each riff has the same letter name as the chord it accompanies.