Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
Q:1/4=120
M:4/4
K:G
['dcBA G2', 'bgfg afdf']  
X:1
L:1/8
Q:1/4=120
M:4/4
K:G
"^Allegro"{B} dcBA G2 G2 | G2 BG FGAe |{e} dcBA G2 d2 | efge{e} dcBc | dcBA G2 G2 | G2 BG FGAe | 
 dcBA G2 d2 | efge dcBd || g3 a bgfg | afdf afdf | g3 a bgfg | afdf g2{agf} g2 | g3 a bgfg | 
 afdf afdf | gabg afdf | gfed efge ||  