Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
Q:1/8=180
M:4/4
K:G
['G2 BG DGBd eg g2 edBd', 'g2 bd gdBd gbaf gdBd ABde']  
X:1
L:1/8
Q:1/8=180
M:4/4
K:G
 (3DEF | G2 BG DGBd | eg g2 edBd | eceg edBG | Ad d2 edcA | G2 BG DGBd | eg g2 edBd | eccB cBAG | 
 FADF G2 :| Bd | g2 bd gdBd | gbaf gdBd | ABde fdde | fdad bdad | g2 bd gdBd | gbaf gdBd | 
 ABde fgfe | cAFA G2 :|  