Build a musical arrangement using the indicated alphabet-based system and the given motif.
X:1
L:1/8
M:6/8
K:A
['a2 a', 'ECA, ECA,']  
X:1
L:1/8
M:6/8
K:A
|: Ace | a2 a aec | ABA Ace | a2 a a2 a | bBB B2 e | gfe gfe | gfe fed | efe dcB | cBA :: a3 | 
 ECA, ECA, | ECA, ECA, | AFD AFD | AFD AFD | EGB EGB | EGB EGB | Ace Ace | aec A :|  