Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:9/8
K:D
['f2 a', 'G2) A2 B']  
X:1
L:1/8
M:9/8
K:D
|: e3- (2:3:2ed f2 a | g2 f (2:3:2ed c(Bc) | d3 (f d2) f2 a | g3 e6 | e3- (2:3:2ed{e} f2 a | 
 g2 f (2:3:2ed c(Bc) | d3 (efg) f(ed) | (fec) d6 :: B3- B2 G B(dB) | A2 G F G2 A(Bc) | 
 d3 (F G2) A2 B | G3 E6 | D2 (E F G2) A2 B | A2 (G F G2) A(Bc) | d3 (efg) f(ed) | (fec) d6 :|  