Develop tuneful melodies adhering to the specified letter notation and including the supplied thematic aspect.
X:1
L:1/8
M:2/4
K:D
['af de f3 f eg', 'eA e2 fA f2']  
X:1
L:1/8
M:2/4
K:D
 af de | f3 f | eg fe | f2 da/b/ | af de | f3 f | eg fe | d4 :: eA e2 | fA f2 | gg/f/ ea | 
 f2 dc/d/ | eA e2 | fA f2 | ed/c/ Be | A2 z a :|  