Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/16
Q:1/4=90
M:2/4
K:C
['GBdf e2c2', 'c2de f2f2 g2g2 a4 agec d2cd']  
X:1
L:1/16
Q:1/4=90
M:2/4
K:C
 Gceg fedB | GBdf e2c2 | e2ec dcBA | GBdf e2c2 | Gceg fedB | GBdf e2c2 | Gcec dcBA | GABG c4 :| 
 c2de f2f2 | g2g2 a4 | agec d2cd | edcB A2G2 | c2de f2f2 | g2g2 a4 | agec d2cd | edBG c4 ||  