Compose a piece of music that follows the specified structure and incorporates the given theme.
X:1
L:1/8
M:4/4
K:C
['g2 af g2', 'd4 GABc d2 dd cdef g2 gg'  
X:1
L:1/8
M:4/4
K:C
 cdef g2 af | g2 af g2 c'2 | cdef g2 fe | e2 d2 d4 :: GABc d2 dd | cdef g2 gg | fedc dcBA | 
 GcBd c4 :|  