Craft a piece of music that integrates both the suggested theme and letter-based structure.
X:1
L:1/8
M:4/4
K:Bb
['F3 D', 'F2 Ge', 'Ge Fd']  
X:1
L:1/8
M:4/4
K:Bb
"^A" B,D | F3 D G3 E | F3 D Ff dB | Ae Ge Ff e/d/c | Bd Gd !breath!!fermata!F2 B,D | F3 D G3 E | 
 F3 D Ff dB | Ae Ge Ff e/d/c | !fermata!B4 z2 ||"^B" d cd | f2 ec fe cg | f2 dB F2 Ge | 
 Fe Ac F2 Ge | Fd Bd !breath!!fermata!f d cd | f2 ec fe cg | f2 dB F2 Ge | Fe Ac Fe dc | 
 !fermata!B4 z4 ||"^C" F Ge | Fe AC EF Ge | Fd BB, D2 Ge | Fe AC EF Ge | Fd Bd !fermata!f F Ge | 
 Fe AC EF Ge | Fd BB, D2 Ge | F2 Ac Fe dc | !fermata!B4 |]  