Craft a musical composition that adheres to the specified musical theme and letter-based structure.
X:1
L:1/8
M:6/8
K:G
['d2 g']  
X:1
L:1/8
M:6/8
K:G
 c |"G" B2 G GBG |"Am" A2 B"^(D7)" c2 e |"G" B2 G"^(Em)" GBG |"Am" ecA"^(D7)" ecA |"G" B2 G GBG | 
"Am" A2 B"^(D7)" c2 e |"G" dBd"C" gfe |"D7" dBG"G" G2 :: c |"G" B2 c d2 g |"C" ece"D7" d2 g | 
"G" BGB"^(Em)" dBG |"Am" ecA"^(D7)" ecA |"G" B2 c d2 g |"C" ece"D7" d2 c |"G" Bcd"C" gfe | 
"D7" dBG"G" G2 :|  