Create music using the given musical theme and adhere to the outlined letter-based structure.
X:1
L:1/8
M:3/8
K:G
['c2 _B A2']  
X:1
L:1/8
M:3/8
K:G
 D | =F2 ^F | G2 A/_B/ | c2 _B | A2 A | _B2 c | dAd | c2 _B | A2 G | dc_e | dA_B | GAG/_E/ | 
 D2 A/_B/ | c_BA | G2 |]  