Craft a musical piece that abides by the prescribed structural guidelines and the given theme.
X:1
L:1/8
M:6/8
K:D
['A2 D FED F2 A A2 f', 'f3 gfe'  
X:1
L:1/8
M:6/8
K:D
 dcB | A2 D FED | F2 A A2 f | g2 e f2 d | e2 d Bcd | A2 D FED | F2 A A2 f | a2 f efe | d3 :| d2 A | 
 d2 e f3 | gfe f3 | gfe f2 d | e2 d Bcd | d2 e f3 | gfe f2 g | a2 f efe | d3 :|  