Construct a music composition that complies with the designated structure and theme.
X:1
L:1/8
M:12/8
K:D
['A def', 'a2 f'  
X:1
L:1/8
M:12/8
K:D
 A | def A2 f a2 f d2 A | def a2 f e3 e2 A | def A2 f a2 f d2 A | def a2 f d3 d2 :| b | 
 b2 a gab a2 f d2 A | def a2 f e3 e2 b | b2 a gab a2 f d2 A | def a2 f d3 d2 :|  