Compose a piece of music using the specified alphabetical notation system and the provided theme.
X:1
L:1/8
M:3/8
K:G
['A2 A']  
X:1
L:1/8
M:3/8
K:G
 D | DDD | G2 G | A2 A | _B2 A | _B2 B | AAA | G2 G | d2 d | d2 d | ccc | _B2 B | A2 A | A2 A | 
 _BBB | G2 A | G2 |]  