Develop a musical composition using both the specified melodic theme and the alphabetical pattern naming.
X:1
L:1/8
M:6/8
K:Dmix
['D3 A3 BAG', 'deB c2 A']  
X:1
L:1/8
M:6/8
K:Dmix
|: D3 A3 | BAG ABA | D3 A3 | BAG EDC | D3 A3 | BAG ABc | dcB cBA |1 BAG EGE :|2 BAG E2 D |: 
 deB c2 A | BAG ABc | deB c2 A | BAG EDC | deB c2 A | BAG ABc | deB c2 A |1 BAG EDC :|2 BAG EGE ||  