Here's a melody that keeps repeating.
___________________________________________________________
-----------------------------------------------------------
    |E|--9-9-9-13--8-8-9-6--|
    |B|---------------------|
    |G|---------------------|    Keep repeating.
    |F|---------------------|
    |A|---------------------|
    |E|---------------------|
----------------------------------------------------------
==========================================================

Or a lower pitch 
------------------------------------------------------
    |E|--3-3-3-7--2-2-2-0---|
    |B|---------------------|
    |G|---------------------|    Keep repeating.
    |F|---------------------|
    |A|---------------------|
    |E|---------------------|
-------------------------------------------------------

well you get the point