Compose a piece of music that follows both the given musical theme and the letter-based structure provided.
X:1
L:1/8
M:4/4
K:C
['G2 A>G']  
X:1
L:1/8
M:4/4
K:C
[M:4/4][K:Gmin] eaue ad9 (e!p!acee udeed)!p! .acca!p! bE a!p! ece deae .e!p! ecfc efeece eE ad e Cef e"^Adagio con expressione" (3.D=EF | 
 G2 A>G G2 FA |"^2" G2 (3FDC D2 (3D^CD |"^3" B/>c/B/A/ B>d c/d/c/=B/ c>e |"^4" d6 G/A/B/c/ | 
"^5" d>=e (3f/g/f/e d>c A>G |"^6" G2 A>G F2 G>A |"^7" B2 (3AGA G2 (3FDC |"^8" D6 (3D=EF | 
"^9" G2 A>G G2 FA |"^10" G2 (3FDC D2 (3D^CD |"^11" B/>c/B/A/ Bd c/d/c/=B/ ce |"^12" d6 (3d=ef | 
"^13" g/a/g/f/ g/a/g/f/ d>c A>G |"^14" G2 A>G F2 d>c |"^15" B2 (3cAG G/A/G/F/ (3D=E^F |"^16" G6 |]  