Develop a musical composition that aligns with the given structural outline and thematic content.
X:1
L:1/4
Q:3/4=90
M:6/4
K:Bb
['f3/2 g/ f', 'B2 c', 'A B c'  
X:1
L:1/4
Q:3/4=90
M:6/4
K:Bb
 G2 G G2 g | f2 e d2 e | f3/2 g/ f c d B | A3 F3 | f3/2 g/ f =e3/2 f/ e | d3/2 e/ d c3/2 B/ A | 
 B3/2 A/ G A ^F2 | G6 :: B2 c d B G | B2 c d B G | B2 c d2 g | ^f3 d3 :: A B c c3/2 d/ c | 
 f2 d A2 A | B c d d3/2 e/ d | g2 f =e3/2 d/ c | f2 f f3/2 e/ d | c2 B A B c | B3/2 A/ G A ^F2 | 
 G6 :|  