Develop a musical composition using the outlined alphabetical depiction of the structure and the provided theme.
X:1
L:1/8
Q:1/8=100
M:2/4
K:G
['dB B/A/G/A/', 'gg d/A/A AG/A/ BB/d/ B/A/G/A/ Bd gg/a/', 'BA Bd g>a bg e2']  
X:1
L:1/8
Q:1/8=100
M:2/4
K:G
 g/e/ | dB B/A/G/A/ | BB Bg/e/ | dB B/A/G/A/ | BA A3/2 z/ |"^5" B z B/A/G/A/ | Bd gg/a/ | 
 bg e/f/g/e/ | dB AG/A/ |"^9" dB B/A/G/A/ | BB Bg/e/ | dB B/A/G/E/ | DG AG/A/ |"^13" B2 B/A/G/A/ | 
 Bd gg/a/ | b/g/g/g/ e/f/g/e/ | dB BA || G/A/ |"^17" Bd gg | Bd d2 | Bd gg | d/A/A AG/A/ | 
"^21" BB/d/ B/A/G/A/ | Bd gg/a/ | b/g/g/g/ e/f/g/e/ | dB (3A/B/A/ :|"^simplified version" g/e/ | 
 dB BA | Bc Bg/e/ | dB Bc | BA A2 |"^5" dB BA | Bd g>a | bg e2 | dB A2 |"^9" dB BA | Bc Bg/e/ | 
 dB BA | DG A2 |"^13" B2 BA | Bd g>a | bg e2 | dB |: G>A |"^17" Bd g>g | Bd d2 | Bd gg | dA GA | 
"^21" Bd BA | Bd g>a | bg e2 |1 dB :|2 dB !fermata!B2 |]  