Develop tuneful melodies adhering to the specified letter notation and including the supplied thematic aspect.
X:1
L:1/8
M:6/8
K:Dmin
['DEF E2 D d2 e f2 g', 'ecg ecg']  
X:1
L:1/8
M:6/8
K:Dmin
|: E | DEF E2 D | d2 e f2 g | agf edc | AcA GEC | DEF E2 D | d2 e f2 g | agf ed^c | d3 D2 :: e | 
 f>ga fga | fga agf | ecg ecg | ecg gfe | f>ga agf | efg gfe | def ed^c | d3 D2 :|  