Compose a piece of music following the specified structure and theme.
X:1
L:1/8
M:2/4
K:Bb
['F F']  
X:1
L:1/8
M:2/4
K:Bb
 B | B3/2 A/ G A | B2 B c/B/ | A F F F | F2 F F | G G G G | B c/B/ A G | d2 d2 | d3 c | B B B c | 
 d2 cB | c c c c | c2 c B/c/ | d d c B | A G A c | B2 G2 | G3 x |]  