Develop a musical piece using the given theme and incorporating the letter-based structure provided.
X:1
L:1/8
M:4/4
K:Ador
['A2 AG ABcd edcB AGEF G2', 'c2 cB cdef gdBc', 'eaa^g a2 =ga bagf e3', 'Ae (3cde', '(3:2:1a3 ae (3a3 ae']  
X:1
L:1/8
M:4/4
K:Ador
|: BG | A2 AG ABcd | edcB AGEF | G2 GF GABc | dBGB edcB | A2 AG ABcd | edcB AGEF | G2 gf edcB | 
 cAAG A2 :: AB | c2 cB cdef | gdBc dBGA | (3BAG dG eGdG | (3BAG dG edcB | c2 cB cdef | gdBc dB GB | 
 A2 ag edcB | cAAG A2 :: cd | eaa^g a2 =ga | bagf e3 g | (3fed ad bdad | (3fed ad bagf | 
 eaa^g a2 =ga | bagf e3 d | (3efg (3fga gedB | cAAG A2 :: AA | Ae (3cde Ae (3cde | 
 Gd (3Bcd Gd (3Bcd | Ae (3cde Ae cd | e^de=d cA BG | Ae (3cde Ae (3cde | ddBG d2 cd | eggf gedB | 
 cdBc A2 :: (3:2:1a3 | ae (3a3 ae (3:2:1g3 | gd (3g3 gd (3:2:1a3 | ae (3a3 ae (3:2:1a3 | 
 aecA e3 B | ceee d2 ed | ceec d2 cd | (3efg fa gedB | ceBc A2 :|  