Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/16
M:2/4
K:Emin
['(GA) BGEG BGEG BAGF E2(FG) AFDF AFDF', 'B2e2 efge']  
X:1
L:1/16
M:2/4
K:Emin
 (GA) | BGEG BGEG | BAGF E2(FG) | AFDF AFDF | AGFE D2(EF) | GFGE g2(fe) | dBGB d2(cB) | AGFE DEFA | 
 G2E2 E2 :: (GA) | B2e2 efge | d2B2 B2(dB) | AB^de faef | d2A2 A2 z2 | B2e2 efge | dBGB d2(cB) | 
 AGFE DEFA | G2E2 E2 :|  