Compose tunes based on the given letter-based musical structure and the supplied motif.
X:1
L:1/8
M:4/4
K:Gmin
['B2 d/c/B', 'DGBG dGBG']  
X:1
L:1/8
M:4/4
K:Gmin
 A | B2 d/c/B fBbB | B2 d/c/B AFcF | B2 d/c/B fBbB | cAFA BGGA | B2 d/c/B fBbB | B2 d/c/B AFcF | 
 B2 d/c/B fBbB | cAFA BGG :: F | DGBG dGBG | DGBG AFcA | DGBG dGBG | cAFA BGG z | DGBG dGBG | 
 DGBG AFcF | DGBG dGBG | cAFA BGG :|  