Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:4/4
K:D
['F2 ED FAA/A/A FAfe dBBA F/F/FED FABc', 'dBBA FAAF A2']  
X:1
L:1/8
M:4/4
K:D
|: F2 ED FAA/A/A | FAfe dBBA | F/F/FED FABc | dBAF E3 F | D2 B,A, B,EE/E/E | FEDE Fefe | 
 dBBA B2 bf | afec dBBA :: FAAF A2 FA | BAfe dBBA | FAAF A2 Bc | dBAF E/E/EEF | DDB,A, B,EE/E/E | 
 FEDE Fefe | dBBA B2 bf | afec dBBA :|  