Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
Q:1/4=120
M:6/8
K:C
['fed fed', 'Bcd Bdd']  
X:1
L:1/8
Q:1/4=120
M:6/8
K:C
[K:D]|:"D" Add fed |"G" gfe"D" fed |"D" Add"Bm" fed |"Em" gee"A" cdB |"D" Add fed |"G" gfe"D" fed | 
"D" fga"Em" gfe |"Bm" fdd"A" cdB ::"D" AFA"G" Bcd |"D" Add"G" Bdd |"D" AFA"Bm" Bcd | 
"Em" efg"A" fed |"D" AFA"G" Bcd |"D" Add"G" Bdd |"D" fga"Em" gfe |"Bm" fdd"A" cdB :|  