Develop tuneful melodies adhering to the specified letter notation and including the supplied thematic aspect.
X:1
L:1/8
M:4/4
K:Gmix
['B2 A>G', 'B<d d>B']  
X:1
L:1/8
M:4/4
K:Gmix
 B2 A>G (3EEE c2 | B2 A>G G>B g>d | B2 A>G (3EEE c2 | d>B A<B G2 G>c :: B<d d>B c>d c>A | 
 B<d d>B (3def g>d | B<d d>B c>d c>A | d>B A<B G2 G>c :|  