Compose tunes based on the given letter-based musical structure and the supplied motif.
X:1
L:1/8
M:6/8
K:G
['dgg dgg', 'dcd gdB']  
X:1
L:1/8
M:6/8
K:G
 dgg dgg | fdc ABc |1 dgg dgg | fdB c3 :|2 dcd gdB | cAF G3 :: dcd gdB | cAG FGA | dcd gdB | 
 cAB c3 | dcd gdB | cAG FGA | def gdB | cAF G3 :|  