Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
M:4/4
K:D
['dcdA FAdA B2 GB', 'fg a2 fa dafd g2 (3fgf edcB']  
X:1
L:1/8
M:4/4
K:D
|: fe | dcdA FAdA | B2 GB AFDF | GABG FAdf | efgf egfe | dcdA FAdA | B2 GB ADFA | BdcB Adfd | 
 ec (3ABc d2 :: fg | a2 fa dafd | g2 (3fgf edcB | ABcd egfe | f2 df e2 fg | a2 fa dafd | 
 g2 (3fgf edcB | ABcd ec (3ABc | (3dcd ec d2 :|  