Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
Q:1/2=80
M:4/4
K:D
['A2 (d3 e f2) A2']  
X:1
L:1/8
Q:1/2=80
M:4/4
K:D
 AG | F2 ED F2 A2 | (d3 e f2) A2 | (B>cd)c (BA) (GF) | TE6 A2 | F2 (ED) (FG) A2 | (d3 e f2) A2 | 
 (B>cd)B c>def | Td6 |:  