Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:4/4
K:D
['E F2 FE FGAB Ad d2 Adfd', 'EDD c defd BcdB cBAc BFFA dF']  
X:1
L:1/8
M:4/4
K:D
|: E | F2 FE FGAB | Ad d2 Adfd | e3 f fedB | BAdf fedB | BAFE F3 B | BAdc defg | afge (3fga ed | 
 cAGE EDD :: c | defd BcdB | cBAc BFFA | dF F2 cFBF | AFED EFGA | EF F2 FGAB | BAdc defg | 
 afge (3fga ed | cAGE EDD :|  