Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
Q:1/2=90
M:4/4
K:C
['B2 b2 B2 gf edcB AGFE', 'Bc dBFB d2 d2 cAFA c2 c2']  
X:1
L:1/8
Q:1/2=90
M:4/4
K:C
 C |[K:Bb] edS Mdc | B2 b2 B2 gf | edcB AGFE | DFBd edcB | A2 f2 f2 dc | B2 b2 B2 gf | edcB AGFE | 
 FABe ceAc | c2 B2 B2 :: Bc | dBFB d2 d2 | cAFA c2 c2 | edef gecB | A2 f2 f2 Bc | dBFB d2 d2 | 
 cAFA c2 c2 | Bbge | dcBA | c2 B2 B2 :|  