Develop a musical piece employing the provided motif and an alphabet-based structure.
X:1
L:1/8
M:4/4
K:Dmix
['', 'dD (3FED FAGF', 'd2 AB']  
X:1
L:1/8
M:4/4
K:Dmix
 FA |: dD (3FED FAGF | EC (3CCC EFGA | dD (3FED FAGF | EDCE D2 FA | dD (3FED FAGF | EDCD EFGc | 
 AddB cBAG |1 ECGE D2 FA :|2 ECGE D2 AB |: dAdf afdf | ecgc acge | dAdf afdf | edce d2 AB | 
 (3ddd df afdf | ecgc acge | abag efge |1 fage d2 AB :|2 fage d2 FA ||  