Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:6/8
K:G
['', 'EFA baf', 'EDB, DFA BAF', 'eag e2 f gfe ebe gfe fdd']  
X:1
L:1/8
M:6/8
K:G
 AG |: E3 EFA | baf gfe | D3 DFA | BAF AFD | EBE EFA | baf g2 b | a3 Bde | fee eAF :| gbe ege | 
 fdc dcd | add fed | fbf afd | bge efg | f3 dcd | BAF AFA | BGE E2 f | g3 ege | fdc d2 B | 
 ADD efg | fbf afa | bge efg | fdB (4:3:4ABcd | B3 FGA | BGE E2 z | EDB, DFA | BAF DED | EFD EDB | 
 DB,A, A,2 B, | EDB, DFA | BAF def | afd Bde | fee egf | EDB, DFA | BAF DED | EFD EDB, | 
 DB,A, A,2 B, | edB Dd^c | BAF def | a2 f gfe | fed eag |: e2 f gfe | ebe gfe | fdd baf | afd def | 
 e3 efe | bef gfe | dBA DFA | BGE E2 f :|  