Craft a musical piece that abides by the prescribed structural guidelines and the given theme.
X:1
L:1/8
Q:1/8=180
M:4/4
K:Amin
['G,A,B,G, A,E E2', 'aecA Ggg^f gdBG'  
X:1
L:1/8
Q:1/8=180
M:4/4
K:Amin
 cB | AE E2 cBAG | E2 DB, G,A,B,G, | A,E E2 A,EAB | cABG ABcB | AE E2 cE E2 | DB, B,2 G,A,B,G, | 
 A,E E2 CEAB |1 cABG AB :|2 cABG A2 || cB | Aaag aecA | Ggg^f gdBG | Aeag aged | ecdB cABG | 
 Aaag aecA | Ggg^f gdBG | AcBd cedf |1 edcB A2 :|2 edcB A4 |]  