Construct a musical piece that complies with the specified structure and abides by genre conventions.
'Sectional: Through Composed'  
X:1
L:1/8
M:3/4
K:A
"^A" AB cd eA | fA eA dA | ce dc BA | G2 FG E2 | Fd Ec DB | CE AG A2 | (3FED CA BG | A6!fine! :| 
"^B" c2 A2 (3ABc | B2 G2 (3GAB | A2 F2 (3FGA | G2 FG E2 | E2 G2 B2 | eg (3gfe b2 | 
 (3agf eg (3fe^d | ef e=d cB ::[K:Amin]"^C""^Trio" A4 (3ABc | B2 e2 B2 | (3cBA A4 | B2 g2 B2 | 
 (3cBA a2 e2 | f2 e2 d2 |1 (3cde dc BA | ^G2 ^FG E2 :|2 ce cA B^G | A6 |:"^D" c2 g2 c2 | B2 g2 B2 | 
 (3edc g2 c2 | (3BAG G4 | a2 c2 a2 | g2 c2 g2 | (3def ed cB | Af ed cB :|  