Compose tunes based on the given letter-based musical structure and the supplied motif.
X:1
L:1/8
M:4/4
K:G
['BGBd gabg agge dedc BGBd', 'G2 ga bagf gbag fed^c defg a2']  
X:1
L:1/8
M:4/4
K:G
 dc | BGBd gabg | agge dedc | BGBd cAFG | AG (3FED FAdc | BGBd gabg | agge dedc | BGBd cAFA | 
 G2 GG G2 :: ga | bagf gbag | fed^c defg | a2 af gbag | fge^c d2 ef | gbaf gage | dedB cedc | 
 BGBd cAFA | G2 GG G2 :|  