Craft a musical piece that abides by the prescribed structural guidelines and the given theme.
X:1
L:1/4
Q:1/4=180
M:2/4
K:Dmix
['E D']  
X:1
L:1/4
Q:1/4=180
M:2/4
K:Dmix
 B,/C/D/ z/ | .D .D | .D .E | =F2 | E/=F/ G | G E | D2 | E D | E/=F/ G | G E | D2 | E D | 
 E/D/E/D/ | E/D/E/D/ | E D | D2 |]  