Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:2/4
K:F
['G F']  
X:1
L:1/8
M:2/4
K:F
 G2 G G | A G F D | G4 | c2 d c | B2 c A | G2 G A | G F E D | F3 G | F4 | d f d c | B2 c2 | 
 d f d c | B2 c A | G2 G A | G F E D | F4 | D F D F | G4 | c3 A | G2 c2 | G A G F | D F2 G | 
 D C B, A, | C4 | D F G F | C4 |]  