Produce a musical expression that follows the indicated alphabetical structure while integrating the provided thematic material.
X:1
L:1/8
Q:3/8=100
M:6/8
K:C
['gec ceg', 'd2 d dcd e2 e']  
X:1
L:1/8
Q:3/8=100
M:6/8
K:C
 gec ceg | afd dfa | gec ceg | dBG G3 | gec ceg | afd dfa | gec fdf | ecc c3 :: d2 d dcd | 
 e2 e ede | fdd ecc | Bdd d3 | d2 d dcd | e2 e ege | dag fed | ecc c3 :|  