Develop a musical piece incorporating the designated alphabet-based pattern and the supplied melodic theme.
X:1
L:1/8
M:2/2
K:D
['D2 (3FED DF A2 dcde fdAF GABG', 'z A,B,CD EFGE (3FED EF GABc dcBA']  
X:1
L:1/8
M:2/2
K:D
 D2 (3FED DF A2 | dcde fdAF | GABG FADF | (3GFE (3FED CE A,2 | D2 (3FED DF A2 | dcde fdAF | 
 GABG FADF | EA,CE D3 z :: A,B,CD EFGE | (3FED EF GABc | dcBA Bcde | fdgf e3 A | d2 fd c2 ec | 
 dcdB AFDF | GABG FADF | EA,CE D3 z :|  