Formulate a musical piece by utilizing the specified motif and alphabet-based structure.
X:1
L:1/4
Q:1/4=120
M:4/4
K:F
['G F']  
X:1
L:1/4
Q:1/4=120
M:4/4
K:F
 G F B c | d c d2 | c d _e d | d c B2 | c2 d2 | B A G F | G4 | F G B2 | c d B A | G F G2 |]  