Craft a musical piece that abides by the prescribed structural guidelines and the given theme.
X:1
L:1/8
Q:1/8=60
M:4/4
K:D
['', 'D/E/F/G/4A/4 B2 BA/G/ A2', 'Adde fd ef/g/'  
X:1
L:1/8
Q:1/8=60
M:4/4
K:D
"^very slow" D/E/F/G/4A/4 || B2 BA/G/ A2 AB/c/ | dcdA GA/G/ FE | D>EFG A>BAG | 
 F2 D2 D2 D/E/F/G/4A/4 | B2 BA/G/ A2 fe | dcdA GA/G/FE | D>EFG A>BAG | F2 D2 D2 || D/E/F/G/ | 
 Adde fd ef/g/ | fdec dcA>G | Adde fd ef/g/ | f2 d2 defg | agf<a g2 fe | d>cde f2 gf/e/ | 
 dc A/G/F G>BAG | F2 D2 D2 |]  