Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:4/4
K:Amix
['eAcA ce', 'cee c Aaec eaec TBABG BcdB Aaec']  
X:1
L:1/8
M:4/4
K:Amix
 f | eAcA ce g2 | dGBG Bddf | eAcA ce Tf2 | eAcA cee :| c | Aaec eaec | TBABG BcdB | Aaec eace | 
 agaA ceeB | Aaec fdec | TBABG Bddf | eAcA aeTfd | cAce aee ||  