Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
M:3/4
K:Bb
['(BD) (FB)', '(BD) (FB)', '(Tf2 e2) f2 g3 (a b>)g (ec)']  
X:1
L:1/8
M:3/4
K:Bb
|: F2 | (BD) (FB) (dB) | (fB) (df) (gf) | (ed) (cB) (Ac) | (BD) (FB) d2 | (BD) (FB) (dB) | 
 (fB) (df) (gf) | (ed) (cB) (Ac) | B4 :: (b2 | c'>)(b a>)(g f2) | b>(f d>)(B c2) | (ec) (AF) (ec) | 
 (BD) (FB) d2 | (BD) (FB) (dB) | (fB) (df) (gf) | (ed) (cB) (Ac) | B4 ::[K:F] c2 | (Tf2 e2) f2 | 
 g3 (a b>)g | (ec) (Bc) (de) | (fA) (cf) (ag) | (Tf2 e2) f2 | g3 (a b>)g | (ec) (Bc) (de) | f4 :|  