Assemble a piece of music by merging the alphabetic representation of the predetermined musical pattern and the provided melodic theme.
X:1
L:1/8
M:6/8
K:Amin
['a2 a gag e2 a a2 g', 'cBA EAB cBA FAB cBA B2 B', 'A d2 d2 cd |1 B3 A3']  
X:1
L:1/8
M:6/8
K:Amin
 a2 a gag | e2 a a2 g | ecc BcB | AFF F3 | EAB cBA | FAB cBA | B2 B edB | Bcd cBA :: EAB cBA | 
 FAB cBA | B2 B edB |1 Bcd cBA :|2 c2 B2 A2 |: d2 d3 c | d c2 B2 A | d2 d2 cd |1 B3 A3 :|2 e3 e3 ||  