Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/16
M:4/4
K:C
['dedc BcBA GFGD EDB,D', 'G2G2G2 (cB) ABAG FGAB cBce defg afge']  
X:1
L:1/16
M:4/4
K:C
[M:2/4][K:G] .a2b2c2 (Bc) | dedc BcBA | GFGD EDB,D | cBce dBgB | AGAB A2(Bc) | dedc BcBA | 
 GFGD EDB,D | GgfedcBA | G2G2G2 :: (cB) | ABAG FGAB | cBce defg | afge fdec | dcde dcBc | 
 dcBd cBAc | BAGF GABc | dgfe dcBA | G2G2G2 :|  