odd + even is the third etude of Common Practice.
Polyrhythms are difficult and even more so on guitar. It is one thing to tap out a 3 against 4 rhythm with two hands, but since sounds created on the guitar require the combination of left and right hand, polyrhythms demand rhythmic independence at the finger level - and both hands have to work together! This etude uses slurs (pull-ons and pull-offs) to facilitate polyrhythmic textures.