Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:6/8
K:G
['f>ed def g3', 'B/c/ d2 d e2 d B2 B']  
X:1
L:1/8
M:6/8
K:G
|: g | f>ed def g3 d2 B | c2 d B2 c A2 A A2 f | f>ed def g3 e2 d | ^c2 c cBc d3 d2 :| B/c/ | 
 d2 d e2 d B2 B d2 c | A2 A AGA B3 G2 B/c/ | d2 d e2 d B2 B d2 c | A2 A ABA G3 G2 ||  