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:4/4
K:F
['Bc dc', 'AG FG']  
X:1
L:1/8
Q:1/4=120
M:4/4
K:F
"Dm" DF Ad fa ge | f2 f2 ff f2 |"Dm" fe d2"Gm" g3 f |"Dm" g2 fe fe d2 | DF Ad fa ge | f2 f2 ff f2 | 
"F" fc cf"Cm" f_e _ed |"^fine""Dm" d8 ::"Dm" (d4 d)c Bc | (d4 d)c Bc | dc Bc dc Bc | dc Bc d4 | 
"D" ab ag .^f2 .^f2 |"Cm" g2 g2"D" ^f4 | ab ag .^f2 .^f2 |"Cm" g^f _eg"D" ^f4 |"C" cd ef ga bb | 
"F" c'a fa"Gm" g3 f |"F" f cc f"Cm" f _e_e d |1"Dm" d6 A2 :|2"Dm" d6"C7" c2 |:"F" FG A4 AB | 
 AB AB A4 |"C" G2 G2 FE DE |"F" F2 z2 c4 | FG A3 Bc d |"Fm" ._e .d.c .B.^G .G.F .E | 
"F" F CC FF"Cm" _E_E D |"Dm" D8 ::"Dm" D4 AG FG | (F4"Cm" F)_E _E/D/C |"Dm" D2 D2 AG FG | 
 (F4"Cm" F)_E _ED |"Dm" D2 D2 AG FG | F2 F2 F2 z2 |"F" FC CF"Cm" F_E _ED |1"Dm" D2 z2 FE DC :|2 
"Dm" D6 z2 ||  