Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
M:6/8
K:G
['A B6- B3- BA B A G2-']  
X:1
L:1/8
M:6/8
K:G
 A | B6- | B3- BA B | A G2- G3 | z2 B BAG | E6- | E3 z2 A | A A2- A3- | A2 F(E/D/) z D/D/ |]  