Develop a musical piece employing the provided motif and an alphabet-based structure.
X:1
L:1/8
M:6/8
K:D
['', 'AFD DFD AFD (G2 E) AFD DF(G', 'd AFD DFD AFD (G2 E) DFA', '', 'Tc3) TB3 A2 D DFA (d2 B)', 'Tc3) TB3 A2 B ABc d2 B']  
X:1
L:1/8
M:6/8
K:D
"^A" |: AFD DFD | AFD (G2 E) | AFD DF(G | A)FD TE2 d || AFD DFD | AFD (G2 E) | DFA (B2 d) | 
 AFD E2 D :|"^B" |: (D/E/F/G/A/B/ Tc3) | TB3 A2 D | DFA (d2 B) | AFD E2 D || (D/E/F/G/A/B/ Tc3) | 
 TB3 A2 B | ABc d2 B | AFD E2 d :|  