Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
Q:1/8=160
M:6/8
K:G
['DGG GFD Dcc cBc ded', 'G2 B/c/ gfg agf d^cd gfg GFG']  
X:1
L:1/8
Q:1/8=160
M:6/8
K:G
 F | DGG GFD | Dcc cBc | ded cAG | FAG FED | DGG GFD | Dcc cBc | ded cAF | AGG G2 :| B/c/ | 
 gfg agf | d^cd gfg | GFG =fef | ABA AGF | GBd g2 f | d2 e fdc | B2 d cAF | AGF G2 :|  