Craft a piece of music that integrates both the suggested theme and letter-based structure.
X:1
L:1/8
M:2/2
K:D
['f2 g2']  
X:1
L:1/8
M:2/2
K:D
|:"D" f2 ef e2 dB | AFAF B2 A2 |"A7" g2 fg f2 ed | BABc (3BcB A2 |"D" f2 ef e2 dB | AFAF B2 A2 | 
"A7" g2 fg f2 ed | B2 c2"D" d4 ::"A7" e2 f2 g2 fe |"D" f2 g2 a4 |"A7" e2 f2 g2 e2 | 
"Em" BABc"A7" (3BcB A2 |"A7" e2 f2 g2 fe |"D" f2 g2 a4 |"A7" e2 f2 gfed | B2 c2"D" d4 :|  