Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
Q:1/4=90
M:3/4
K:G
['B3 G']  
X:1
L:1/8
Q:1/4=90
M:3/4
K:G
 B>c |"G" d3 B e>d |"D7" d2 c2 A>B | c3 e d>c |"G" B4 G>A | B3 G c>B |"D7" B2 A2 F>G | A3 c B>A | 
"G" G2 z2 || G>B ||[M:4/4]"D" A4- A^G A>c |"G" B6 B>d |"A" ^c4- c>^B"A7" c>e | 
"D7" d4- !fermata!d2 d>c |"G" B3 G A2"G7" B2 |"C" c2 e4 d>c |"G/D" B3 G"D7" A3 F |"G" G4 z2 |]  