Develop a musical composition based on the provided pattern of letters and incorporating the given motif within it.
X:1
L:1/8
M:4/4
K:D
['DB,A,B, D2', 'BAAd BdAd', 'fa a2']  
X:1
L:1/8
M:4/4
K:D
 DB,A,B, D2 EA | FAEA DB, B,2 | DB,A,B, D2 FE | DG,B,D B,A, A,2 :: BAAd BdAd | fAeA dB B2 | 
 BAAd BdAd | fbea d2 d2 :: fa a2 fbea | defd BABd | fa a2 ba a/a/a | fbaf e2 de | fa a2 fbea | 
 defd BAFA | BAFB AFAd | fbea d2 d2 :|  