Develop a musical piece that combines the given theme and letter-structured outline.
X:1
L:1/8
M:4/4
K:D
['FD D/D/D', 'A/A/A ageg f2 ff =cdAc dAGA af']  
X:1
L:1/8
M:4/4
K:D
|: dBAG FD D/D/D | EFGE FD D/D/D | EFGA Bdef | gfed cA A/A/A | dfed =c2 cA | BAGA FD D/D/D | 
 =F3 G A=cde | =fede cA A/A/A :: ageg f2 ff | =cdAc dAGA | af (3gfe fedB | =c3 c BAGA | ageg ffff | 
 =cdAc dAGE | =F3 G A_B=cA | A/A/A =cA A/A/A ^cA :|  