Craft a musical piece in accordance with the designated structure and theme.
X:1
L:1/8
Q:1/8=180
M:4/4
K:G
['AD D2', 'cdec dcAG'  
X:1
L:1/8
Q:1/8=180
M:4/4
K:G
"^D modal" EG | AD D2 AGEF | GcAG EFGE | AD D2 cDBD | (3ABc AG c2 Bc | AD (3DED AGEF | 
 Gc c2 d2 cd | ecdB cAGE | (3ABc GE D2 :|[K:C]"^D dorian" z G | ADcD =BDAG | cdec dcAG | 
 cdec dcAG | gece d2 de | fage dcAG | cEAG EAGE | ecd=B cAGE | AcGE D2 :|  