Formulate a musical piece by utilizing the specified motif and alphabet-based structure.
X:1
L:1/8
Q:1/8=100
M:2/4
K:A
['A2 AE CE AG FB', 'a2 ae ceag', '', 'cA/c/ ec/e/ ac eddB', 'ec cB/c/']  
X:1
L:1/8
Q:1/8=100
M:2/4
K:A
"^A" A2 AE | CE AG | FB BA | GA Bc | A2 AE | CE AG | FB FG | AB/c/ d/e/f/g/ || a2 ae | ceag | 
 fbba | gabc' | a2 ae | ceag | fbag | a2 a ||"^final" a2 a2 |]"^B: \"1st and 3rd\"" c/B/ | 
 AE/A/ cA/c/ | ec/e/ ac | eddB | fe c/d/c/B/ | AE/A/ cA/c/ | ec/e/ ac | eddB | BAAc | eddB | 
 fe cA/c/ | eddB | fe c/d/c/B/ | AE/A/ cA/c/ | ec/e/ ac | eddB | BAA z || 
"^C: \"2nd and 4th\"" c/d/ | eaa g/f/ | ec cB/c/ | df fe/d/ | cA A(3B/c/d/ | ea ag/f/ | ec cB/c/ | 
 dffe | A3 z | AE/A/ ce | dBB>A | GE/G/ Bd | cA A/d/c/B/ | AE/A/ cd | cBB>A | Gff>e | A2 A z ||  