Compose tunes based on the given letter-based musical structure and the supplied motif.
X:1
L:1/8
Q:1/8=232
M:4/4
K:D
['Dd dc cB BA', 'A,D A,D B,D', 'ab af', 'BA AG GF']  
X:1
L:1/8
Q:1/8=232
M:4/4
K:D
|: Dd dc cB BA | af df ed ef | Dd dc cB BA | AF EF D2 D2 :: A,D A,D B,D B,D | A,D GA B/A/G/F/ EF | 
 A,D A,D B,D GB | AF EF D2 D2 :: ab af df df | g/b/g f/a/f ed ef | ab af de fd | Bg fe d2 d2 :: 
 BA AG GF FE | D/E/F/G/ AF ED EF | BA AG GF ED | B,B AF D2 D2 :|  