Utilizing the provided musical theme and letter-based structure, compose a piece of music.
X:1
L:1/8
M:4/4
K:D
['BAFE D2 DE', 'e2 fded']  
X:1
L:1/8
M:4/4
K:D
 BAFE D2 DE | FABc d2 ed | BAFE D2 DE | FABA FE E2 | BAFE D2 DE | FABc d3 e | fdec dcBA | 
 BdAF FE E2 || Be e2 fded | Beed BdAd | de e2 fded | BdAF DEFA | Be e2 fded | Beec d3 e | 
 fddf edBA | FABc d2 ed ||  