Craft a piece of music that integrates both the suggested theme and letter-based structure.
X:1
L:1/16
M:2/4
K:Bb
['d(BAB) F(BAB) FBGB', 'B2B2B2 (de) |{g} f=efg f2ga bBaB gBfB']  
X:1
L:1/16
M:2/4
K:Bb
 (fe) | d(BAB) F(BAB) | FBGB F(BAB) | (cB)(dc) (ge)cA | Bdfd gfec | d(BAB) F(BAB) | FBGB FBAB | 
 (cB)(dc) gecA | B2B2B2 || (de) |{g} f=efg f2ga | bBaB gBfB | edcd efga | bBAc BAGF | 
 d(BAB) F(BAB) | FBGB FBAB | (cB)(dc) gecA | B2b2B,2 ||  