Craft a musical piece that abides by the prescribed structural guidelines and the given theme.
X:1
L:1/8
M:2/4
K:D
['A2 A>B AF ED', 'Ad fa'  
X:1
L:1/8
M:2/4
K:D
 FG | A2 A>B | AF ED | f2- f>d | ed Bd | A2 A>B | AF ED | E2 E>F | E2 DF | A2 A>B | AF ED | 
 f2- f>d | ed Bd | A2 d>e | fe dc | d2 d>e | d2 || Ad | f>e fa | Ad fa | g2 f2 | e2 f>g | af dA | 
 FA GF | E2 E>F | E2 FG | AD FA | dF Ad | fa gf | ed cB | Aa ^ga | ge cA | d2 d>e | d2 ||  