Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:2/4
K:Bb
['(B>c) (.d.g) |{=efg} (f>_e) .d(B/c/) |{^c} d>=c{d}', '(.g.b) (a>f) (.d.c) (df).f (F/>G/) (B>c) .d.f']  
X:1
L:1/8
M:2/4
K:Bb
 (F/>A/) | (B>c) (.d.g) |{=efg} (f>_e) .d(B/c/) |{^c} d>=c{d} (cB)(GF) | (GB){A}B F | 
 (B>c) (.d.g) |{=efg} (f>_e) .d(B/c/) |{^c} d>=c{d} (c/B/)(G/F/) | (GB){A}B || .f | (g>f) (ga) | 
 (b>a) (gb) |{^fga} (g>=f) (.d.c) |{^c} (Bg).g f |{a} (g>f) (.g.a) | (b>a) (.g.b) | 
{^gab} (a>f) (.d.c) | (df).f (F/>G/) | (B>c) .d.f |{=efg} (f>_e) .d(B/c/) | 
{Bc} (d>c){d} (c/B/)(G/F/) | GB{A}!fermata!B ||  