Compose a piece adhering to the given musical structure and theme.
X:1
L:1/8
M:3/8
K:F
['AFA BGF', 'faf gbg'  
X:1
L:1/8
M:3/8
K:F
 c | AFA | BGF | ECE F2 c/B/ | AFA | BGF | ECE | F2 :| c | faf | gbg | agf | edc | faf | gbg | 
 ece | f2 :|  