Formulate a musical piece by utilizing the specified motif and alphabet-based structure.
X:1
L:1/8
Q:1/8=180
M:2/2
K:G
['G2 BG', 'fdef g2 bg dgbg dega bg g2']  
X:1
L:1/8
Q:1/8=180
M:2/2
K:G
 G2 BG DGBG | D2 (3FED dAFA | G2 BG DGef |1 (3gfe dc BGAF :|2 (3gfe dc BG G2 || g2 bg dgbg | 
 fgag fdef | g2 bg dgbg | dega bg g2 | dgbg dgbg | fgag fdef | gaba gedc | (3Bcd AG FDEF |]  