Craft a piece of music that integrates both the suggested theme and letter-based structure.
X:1
L:1/8
M:6/8
K:D
['', 'DEF DEF', 'AEF G3 GFE']  
X:1
L:1/8
M:6/8
K:D
 DEF |: DEF DEF | G3 EFG | EFG EFG | A3 DEF | DEF DEF | G3 EFG | A3 GFE |1 D3 DEF :|2 D3 DED || 
 B3 B FG | A3 AEF | G3 GFE | A3 DED | B3 B FG | A3 AEF | G3 GFE |1 D3 DED :|2 D3 DEF ||  