Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
Q:1/8=232
M:4/4
K:D
['fe dB AF AD']  
X:1
L:1/8
Q:1/8=232
M:4/4
K:D
|: B | AF ED dF ED | EB BA BE Ed | AF ED de fe | dB AF AD DB | AF ED dF ED | EB BA BE Ed | 
 AF ED de fe | dB AF AD Df | ab af de fd | eb ba be ef | ab af de fe | dB AF AD Df | ab af de fd | 
 eb ba be ef | ab ef dg fe | dB AF AD D :|  