Craft a musical piece that abides by the prescribed structural guidelines and the given theme.
X:1
L:1/8
M:4/4
K:G
['B G3 DEGA Bdgd', 'G2 bgaf g4 e a3 eaga bgaf'  
X:1
L:1/8
M:4/4
K:G
 c | B G3 DEGA | Bdgd cAAc | B G3 DEGA | Bdgd BGGA | B3 d c3 A | Bdgd cAAc | B G3 DEGA | 
 Bdgd BG G2 || bgaf g4 | e a3 eaga | bgaf gfed | ^cde=c B/c/d ga | bgaf gbfg | ea a/a/a eaab | 
{c'} babe agef | gbag{a} gedc ||  