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
['GB B2 cBAB', 'G2 BG A2 GA BcAc BG']  
X:1
L:1/8
Q:1/8=180
M:2/2
K:G
 GB B2 cBAB | GBdg e2 d2 |1 GB B2 cBAB | eA A2 eA A2 :|2 G2 BG A2 GA | BcAc BG G2 |: f2 fd e2 ed | 
 gfge dBGB | f2 fd e2 ed | eA A2 eA A2 |1 f2 fd e2 ed | gfge dBGB | G2 BG A2 GA | BcAc BG G2 :|2 
 gaba gfed | efge dBAB | G2 BG A2 GA | BcAc BG G4 |]  