Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
Q:1/8=150
M:2/2
K:Amin
['', 'A2 AG', '', 'A2 AG']  
X:1
L:1/8
Q:1/8=150
M:2/2
K:Amin
 ed |: c2 EF G2 EF | GFGA GAcd | egec AdcA | G^FEF G2 FG | AGAB cBcA | dcde g2 ^fg | a=fge fdec |1 
 A2 AG AGAB :|2 A2 AG Ac ||[K:D]"^A modal" |: ef | gfga gfed | cdef gfed | eaab [ac']bag | 
 e2 a2 a2 ef | geaf gedB | cdef g2 ^fg | afge fdec |1 A2 AG Ac :|2 A2 AG A4 |]  