Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:2/4
K:A
['E A>Bcc dB c2 cBB A/B/ cBB', 'AFF e (fa) (ef) (d/c/)B/A/{AB} c2 cBB', "AFF e a>b c'c' d'b c'2 c'bb", 'fa ea']  
X:1
L:1/8
M:2/4
K:A
 E | A>Bcc | dB c2 | cBB A/B/ | cBB A/F/ | A>B cc | dB c>B | AFF E/F/ | AFF :| e | (fa) (ef) | 
 (d/c/)B/A/{AB} c2 | cBB A/B/ | cB B>e | fa ea | (d/c/)B/A/ c>B | AFF E/F/ | AFF :: e | a>b c'c' | 
 d'b c'2 | c'bb a/f/ | d'b c'>b | aff e/f/ | aff :: ag | fa ea | (d/c/)B/A/{AB} c2 | cBB A/B/ | 
 cB B>e | fa ea | (d/c/)B/A/ c>B | AFF E/F/ | AFF :|  