Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
Q:1/4=120
M:2/2
K:F
['(c2 D2) (FG)']  
X:1
L:1/8
Q:1/4=120
M:2/2
K:F
"^With expression" (Ac) | (dedc A2) (GA) | c2 (c2 D2) (FG) | (A2 c).A (GBAG) | (F3{AG} F2) (Ac) | 
 (dedc) (A2{BA} G).A | .c2 (c2 D2) (FG) | (A2{BA^GA} c).A (=GB){B} (AG) | (F4{AG} F) z (FG) | 
 (A3 c f2){gf} (ef) | (gfef) .d2 (cB) | (Ac).d.e (f3 e) | (d4 c) z (Ac) | (d_edc) (A2{BA} G).A | 
 .c2 (c!fermata!D) (FG) | (A2{BA^GA} c).A (=GBA).G | F6 ||  