Develop a musical composition utilizing the presented motif and adhering to the required structure.
X:1
L:1/8
M:2/4
K:Bb
['F B>dc>B f>dB>e d>cB>A Bfg_a g>eE>g f>dD>f', 'c2) c f>ed>c =B>_AG>F E>_ag>f e>dc>d e>dc>B'  
X:1
L:1/8
M:2/4
K:Bb
 F | B>dc>B | f>dB>e | d>cB>A | Bfg_a | g>eE>g | f>dD>f | d>BA>B | (B c2) :: c | f>ed>c | 
 =B>_AG>F | E>_ag>f | e>dc>d | e>dc>B | A>GF>E | D>ed>g | f>AB>a | b>fd>B | g>ec>A | f>CA>c | 
 B2 F2 | G>BA>c | B>ed>c | d>BF>A | B3 :|  