Design a musical composition incorporating the alphabetic expression of the chosen structure and the provided melodic theme.
X:1
L:1/8
Q:1/4=100
M:4/4
K:G
['G3 A']  
X:1
L:1/8
Q:1/4=100
M:4/4
K:G
 D2 |"G" G3 A BD"C" E>c |"G" B6 B2 | d3 e dG"A7" BA |"D" A6 D2 |"G" G3 A BD G>A | 
 (B2 c2 d2)"C" e2 |"G/D" d3 c"D7" B2 A2 |"G" G4 z2 G2 ||"G" B3 c BA G>F |"C" E6 E2 | 
"G" G3 A Bc d>B |"D" A6"D7" D2 |"G" G3 A BD G>A | (B2 c2 d2)"C" e2 |"G" d3 c"D7" B2 A2 | 
"G" G4 z2 |]  