Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
Q:3/8=100
M:6/8
K:G
['GEA GED']  
X:1
L:1/8
Q:3/8=100
M:6/8
K:G
 GEA GED | B,DB, (DE)F | GEA GED | B,EE E2 F/F/ | GEA GED | B,DB, D(DF) | GAB cBA | 
 GEE E2 (B/^c/) | ded dBA | GEF (GA)B | Bee edB | BAA A2 B/^c/ | ded dBA | GEF GAB | cBA (GE)D | 
 B,EE E3 ||  