Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/16
M:3/8
K:C
['e4 ef g2 g4', 'e4 ef e2 c4']  
X:1
L:1/16
M:3/8
K:C
 e4 ef | g2 g4 | fga2g2 | fed2c2 | e4 ef | g2 g4 | agf2e2 | d6 :: e4 ef | e2 c4 | ded2c2 | Bcd2d2 | 
 e4 ef | e2 c4 | ded2B2 | c6 :|  