Develop a musical piece employing the provided motif and an alphabet-based structure.
X:1
L:1/8
M:4/4
K:G
['(GA) B3 B B3 A (AG) G2']  
X:1
L:1/8
M:4/4
K:G
 (GA) | B3 B B3 A | (AG) G2 G2 (GB) | dd d2 (dB) (Bd) | g6 ||  