Craft a musical piece that abides by the prescribed structural guidelines and the given theme.
X:1
L:1/16
Q:1/8=180
M:2/4
K:D
['G2B2 BGBG F2A2 AFAF', 'f2d2f2d2 fdfg a4'  
X:1
L:1/16
Q:1/8=180
M:2/4
K:D
|: G2B2 BGBG | F2A2 AFAF | G2e2e2d2 | cdec A4 | G2B2 BGBG | F2A2 AFAF | dcde dBAG | F2D2 D4 :: 
 f2d2f2d2 | fdfg a4 | ecAc ecAc | ecef g4 | f2d2f2d2 | fdfg a4 |1 efec dedB | c2A2 A2Ad :|  