Craft a musical piece in accordance with the designated structure and theme.
X:1
L:1/8
M:6/8
K:D
['DFA B2 A def g2 e fdf', 'faa faa'  
X:1
L:1/8
M:6/8
K:D
 DFA B2 A | def g2 e | fdf ecA | BGB AFD | DFA B2 A | def g2 e | fdf ecA | Add d3 :: faa faa | 
 faa agf | e=ce e=ce | efg gfe | fef gfg | afd efg | fed =cAG | Add d3 :|  