Construct a melodic piece using the designated alphabetic pattern and the provided musical theme.
X:1
L:1/8
M:6/8
K:C
['c cBc', 'c2 c g2 g gfe fga a2']  
X:1
L:1/8
M:6/8
K:C
 G | c2 c cBc | ABc def | e2 c cBc | B2 G GAB | c2 c cBc | ABc def | Adc BAB | c3- c2 :: c | 
 g2 g gfe | fga a2 c' | gec cBc | d2 G GAB | EGc cBc | Acf fga | g2 c dcd | e2 c c2 :|  