Generate harmonious tunes by incorporating the specified letter-based framework and the presented motif.
X:1
L:1/4
M:4/4
K:G
['G G']  
X:1
L:1/4
M:4/4
K:G
 G G G | A2 A _B | G2 =F2 | z =F _B3/2 c/ | d3/2 c/ d c/_B/ | A d d d | c d2 c/A/ | =F3 G | 
 A _B c2 | c _B A3/2 G/ | G4 | z |]  