Develop a musical piece that combines the given theme and letter-structured outline.
X:1
L:1/8
Q:1/2=75
M:4/4
K:D
['dfed cBAG FAGE', '(3efe (3dcB Abag (3fgf (3efe']  
X:1
L:1/8
Q:1/2=75
M:4/4
K:D
 (3ABc | dfed cBAG | FAGE DFAd | cdef gfed | caec ABcA | dfed cBAG | FAGE Dfed | cbag fedc | 
 d2 f2 d2 :: f2 | (3efe (3dcB Abag | (3fgf (3efe dagf | (3efe (3dcB Abag | (3fgf (3efe dafd | 
 BGBd gfed | efga bagf | (3fgf df (3eba (3gfe | d2 f2 d2 :|  