Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
M:4/4
K:C
['BEA Dec |[M:2/2][K:G]SOSOO .!fermata!PMTCO Mc BG', 'BG (3(GGG)', 'BG (3(GGG)', 'fgaf gfgd BGBd AGFG ABcA g3 d', 'Bdgd Bdgd', 'Acfc Ac=fc A=FFA Bdgd Bdgd g3 a', 'gedc AGFG ABcA']  
X:1
L:1/8
M:4/4
K:C
 BEA Dec |[M:2/2][K:G]SOSOO .!fermata!PMTCO Mc |: BG (3(GGG) (BG)cG | BG (3(GGG) (Bdg)d | 
 BG (3(GGG) (BG)dB | AGFG ABcA :: BG (3(GGG) (BG)cG | BG (3(GGG) (Bdg)d | BG (3(GGG) (BG)dB | 
 AGFG ABcA ::"^~" g3 d BGBd | g2({a} ge) fgaf | gfgd BGBd | AGFG ABcA ||"^~" g3 d BGBd | 
 g2({a} ge) fgag | bgaf gedB | AGFG ABcA || Bdgd Bdgd | Bdgd BGGB | Ac=fc Acfc | Ac=fc A=FFA || 
 Bdgd Bdgd | Bdef"^~" g3 a | bgaf gedc | AGFG ABcA :| G6 |]  