Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:6/8
K:Amix
['(3A/B/c/ dAF FAF FAF F2 d AFE', 'cAe cAe', 'd cBA BAF', 'cAA eAA']  
X:1
L:1/8
M:6/8
K:Amix
 (3A/B/c/ | dAF FAF | FAF F2 d | AFE EFE | EFE EFA | dAF FEF | DFA d2 e | fed cdB | A3 A2 :| d | 
 cAe cAe | cAe edc | dBf dBf | dBf fed | cAe cAe | cAe e2 a | fed cdB | A3 A2 :| d | cBA BAF | 
 dAF D2 d | cBA BAF | AFE E2 d | cBA BAF | DFA d2 e | fed cdB | A3 A2 :| d | cAA eAA | 
 (f/g/a)f edc | dBB fBB | (f/g/a)f fed | cAA eAA | fAA cea | fed cdB | A3 A2 :|  