Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
Q:1/4=150
M:3/8
K:G
['D2 G2 FG BG B2 d^c dB', 'd2 ed cB cA B2 BG Bd']  
X:1
L:1/8
Q:1/4=150
M:3/8
K:G
 D2 | G2 FG BG | B2 d^c dB | AB cA FA | B2 G2 D2 | G2 FG BG | B2 d^c dB | AB cA FA | G4 :| d2 | 
 ed cB cA | B2 BG Bd | c2 AF Ac | B2 G2 d2 | ed cB cA | B2 BG Bd | c2 af af | G4 :|  