Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:6/8
K:G
['GED D3 GEG c2 e dBG GAB', 'e dBG GAB']  
X:1
L:1/8
M:6/8
K:G
 GED D3 | GEG c2 e | dBG GAB | AGE E3 | GED D3 | GEG c2 e | dBG GAB |1 AGF G3 :|2 AGF G2 d |] 
 gdB GBd | gdB c2 e | dBG GAB | AGE E3 | gdB GBd | gdB c2 e | dBG GAB | AGF G2 d | gdd gdd | 
 gdB c2 e | dBG GAB | AGE E3 | GED D3 | GEG c2 e | dBG GAB | AGF G3 |]  