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
['D (DE) F G A3', 'A, A, D2'  
X:1
L:1/8
M:2/4
K:D
 D | (DBA) G | (F2 E) D | (DE) F G | A3 D | (DB) A G | F2 E D | (DE) F G | A3 A | (BG) d B | 
 A2 F F | (GF) E F | G2 (FG) | (Ad) B G | A2 G F | (ED) (FE) | D2 || A, A, | D2 E2 | A,2 A, A, | 
 D2 (EF) | G2 F G | (Ad) B G | A2 G F | (ED) F E | D3 ||  