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
['(f/g/) afd ecA d2 A A2', 'D2 (F/G/) AFA BGB AFA d2 A'  
X:1
L:1/8
M:6/8
K:D
 (f/g/) | afd ecA | d2 A A2 =c | BGB AGF | E2 E E2 (f/g/) | afd ecA | d2 A A2 G | FDF ECE | 
 D3 D2 :| (F/G/) | AFA BGB | AFA d2 A | BGB AGF | E2 E E2 (f/g/) | afa geg | fdf ecA | 
 (B/c/d)B (c/d/e)c | d3 d2 :|  