Form a musical piece based on the provided motif while observing the defined structure.
X:1
L:1/8
M:4/4
K:G
['BGGB cAAc', 'dBdg eceg fdef'  
X:1
L:1/8
M:4/4
K:G
 dc |[M:4/4] BGGB cAAc | BGGc Bdgd | BGGB cAAc | Bgd^c d3 :: e | dBdg eceg | fdef gage | 
 dBdg eceg | fdef g2 fe | dB B2 ec c2 | dB B2 AFDd | edef gage | dBcA G4 :|  