Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/4
Q:1/4=88
M:3/4
K:G
['(vG,3/2 A,/) B, (D3/2 C/) B, C2', '([GG,]3/2 A/) B']  
X:1
L:1/4
Q:1/4=88
M:3/4
K:G
|:"^Andante" (vG,3/2 A,/) B, | (D3/2 C/) B, | C2 ^C | (D3/2 E/) F | ([GG,]3/2 A/) B | (d3/2 c/) B | 
 (C/A,/) D (E/4D/4^C/4D/4) | D2 G,2 z :: v[EC] [EC] [EC] | [DC] [DC] [DC] | [FA,] (.[FA,] .[FA,]) | 
 ([GG,]3/2 A/) B | c C z | vG G, z | vG, A, B, | C D/E/ F | [GG,] z z | (v[dDG,]3/2 c/) B | C2 ^C | 
 (D3/2 E/) F | ([GG,]3/2 A/) B | (d3/2 c/) B | (C/A,/) D D | (D G,) z :|  